Sepiapterin reductase inhibitors for the treatment of pain

ABSTRACT

Disclosed herein are small molecule heterocyclic inhibitors of sepiapterin reductase (SPR), and prodrugs and pharmaceutically acceptable salts thereof. The Also featured are pharmaceutical compositions of the compounds and uses of these compounds for the treatment or prevention of pain (e.g., inflammatory pain, nociceptive pain, functional pain, and neuropathic pain).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a filing under 35 U.S.C. §371 of PCT/US2010/052674filed with the Patent Cooperation Treaty on Oct. 14, 2010, which claimspriority to and benefit of U.S. Provisional Application No. 61/252,013,filed Oct. 15, 2009, all of which is herein incorporated in theirentirety by reference.

BACKGROUND OF THE INVENTION

In general, the present invention relates to small molecule heterocyclicinhibitors of sepiapterin reductase (SPR), and to the medical use ofthese compounds.

Tetrahydrobiopterin (BH4), which has the following structure,

is an essential cofactor of hydroxylase enzymes that are involved in thesynthesis of neurotransmitters such as serotonin, melatonin, dopamine,norepinephrine (noradrenaline), epinephrine (adrenaline), and nitricoxide (NO). SPR catalyzes the final step in the BH4 synthetic pathway,which is the conversion of 6-pyruvoyl tetrahydropterin to BH4. SPR isalso one of the two enzymes involved in de novo BH4 synthesis that isup-regulated in preclinical pain models, and reducing the activity ofthese enzymes leads to preclinical pain relief (Tegeder et al., NatureMedicine 12:1269-1277, 2006). Accordingly, the inhibition of SPR can bea useful target for developing new methods for the treatment orprevention of pain.

SUMMARY OF THE INVENTION

In general, in a first aspect, the invention features compounds having astructure according to Formula (I),

or a prodrug or pharmaceutically acceptable salt thereof, where

each of X¹ and X² is, independently, N, C—H, or C-halogen;

A is a single bond, C(═O), or SO₂;

R¹ is (CH₂)_(n)OR^(1A), halogen (e.g., F, Cl, Br, or I, preferably Cl),amino (e.g., NH₂), CN, SO₂R^(1A), NHSO₂R^(1A), NHC(═O)R^(1A), orC(═O)N(R^(1A))₂;

each R^(1A) is, independently, H or optionally substituted C₁₋₆ alkyl;

n is 0, 1, or 2;

R² is CH₂OR^(2A), optionally substituted C₁₋₆ alkyl, optionallysubstituted C₃₋₉ cycloalkyl, optionally substituted aryl, optionallysubstituted heterocyclyl, or optionally substituted heteroaryl;

R^(2A) is H or optionally substituted C₁₋₆ alkyl;

R^(3A) and R^(3B) are both H, or R^(3A) and R^(3B) combine to form ═O;

R^(4A) and R^(4B) are both H, or R^(4A) and R^(4B) combine to form ═O;

each of R⁵ and R⁶ is, independently, H, optionally substituted C₁₋₆alkyl, optionally substituted C₃₋₁₀ cycloalkyl, optionally substitutedalkaryl, or optionally substituted alkheteroaryl; and

where when A is C(═O), R¹ is OH, R² is CH₂OMe, R^(3A), R^(3B), R^(4A),and R^(4B) are each H, and R⁵ is H, R⁶ is not H.

In some embodiments, one and only one of R^(3A) and R^(3B) and R^(4A)and R^(4B) can combine to form ═O.

In other embodiments, one or both of X¹ and X² is C—H, or one or both ofX¹ and X² is C—Cl.

In certain embodiments, R⁵ and R⁶ is, independently, H, branched C₁₋₆alkyl, aminoalkyl, alkoxyalkyl, or haloalkyl.

In some embodiments, the compound has a structure according to Formula(I-A),

or a prodrug or pharmaceutically acceptable salt thereof, where R¹ is(CH₂)_(n)OR^(1A), halogen, CN, SO₂R^(1A), NHSO₂R^(1A), orC(═O)N(R^(1A))₂; R⁵ is H or optionally substituted C₁₋₆ alkyl; R⁶ is Hor optionally substituted C₁₋₆ alkyl; and where one and only one ofR^(3A) and R^(3B) and R^(4A) and R^(4B) can combine to form ═O.

In certain embodiments, R¹ is OH, CH₂OH, F, CN, SO₂CH₃, NHSO₂CH₃, orC(═O)NH₂.

In other embodiments, R² is (CH₂)_(m)OR^(2B), wherein m is 1, 2, or 3,and R^(2B) is H or optionally substituted C₁₋₆ alkyl.

In some embodiments, R⁵ is H or CH₃.

In other embodiments, R⁶ is H or CH₃.

In still other embodiments, R^(3A), R^(3B), R^(4A), and R^(4B) are eachH.

In certain embodiments, R^(3A) and R^(3B) combine to form ═O. In otherembodiments, R^(4A) and R^(4B) combine to form ═O.

In certain embodiments, the compound has a structure according to thefollowing formula:

or a prodrug or pharmaceutically acceptable salt thereof, where R¹ isOH, CH₂OH, F, CN, SO₂R^(1A), NHSO₂R^(1A), or C(═O)NH₂; R^(1A) isoptionally substituted C₁₋₃ alkyl; R² is optionally substituted C₃₋₆alkyl, optionally substituted C₃₋₆ cycloalkyl, optionally substituted5-6 membered heterocyclyl, or optionally substituted heteroaryl; R⁵ is Hor CH₃; and R⁶ is H or optionally substituted C₁₋₃ alkyl.

In some embodiments, the compound of Formula (I) has the followingstructure:

In some embodiments, the compound has a structure according to thefollowing formula:

or a prodrug or pharmaceutically acceptable salt thereof, where R¹ isOH, CH₂OH, F, CN, SO₂R^(1A), NHSO₂R^(1A), or C(═O)NH₂; R^(1A) isoptionally substituted C₁₋₃ alkyl; R² is optionally substituted C₁₋₆alkyl or optionally substituted C₃₋₆ cycloalkyl; R⁵ is H or CH₃; and R⁶is H or optionally substituted C₁₋₃ alkyl. In some embodiments, R¹ isOH, and R⁵, and R⁶ are each H. In some embodiments, the compound isselected from the group consisting of:

In still other embodiments, the compound has a structure according tothe following formula:

or a prodrug or pharmaceutically acceptable salt thereof, where R¹ isOH, CH₂OH, F, CN, SO₂R^(1A), NHSO₂R^(1A), or C(═O)NH₂; R^(1A) isoptionally substituted C₁₋₃ alkyl; R² is optionally substituted C₁₋₆alkyl or optionally substituted heteroaryl; and R⁶ is H or optionallysubstituted C₁₋₃ alkyl. In some embodiments, R¹ is OH and R⁶ is H. Inother embodiments, R² is optionally substituted pyridyl or C₁₋₃ alkylthat includes a C₁₋₂ alkoxy substituent. In some embodiments, thecompound is selected from the group consisting of

In a second aspect, the invention features further compounds having astructure according to Formula (II),

or a prodrug or pharmaceutically acceptable salt thereof, where

X is N or CH;

m is 0 or 1;

R¹ is (CH₂)_(n)OR^(1A), halogen, CN, amino (e.g., NH₂), SO₂R^(1A),NHSO₂R^(1A), NHC(═O)R^(1A), or C(═O)N(R^(1A))₂;

each R^(1A) is, independently, H or optionally substituted C₁₋₆ alkyl;

n is 0, 1, or 2;

R² is H or optionally substituted C₁₋₃ alkyl;

R³ is H, C(═O)R^(3A), or SO₂R^(3A); and

R^(3A) is optionally substituted C₁₋₆ alkyl.

In some embodiments, the compound has a structure according to any ofthe following formulas:

or a prodrug or pharmaceutically acceptable salt thereof. In certainembodiments, X is N, m is 1, and R² is H. In other embodiments, R¹ isamino. In some embodiments, R³ is C(═O)R^(3A), and R^(3A) is C₁₋₃ alkylthat includes a C₁₋₃ alkoxy substituent. In further embodiments thecompound is

In some embodiments, X is CH, m is 1, and R² is H. In other embodiments,R¹ is F, OH, CN, CH₂OR^(1A), SO₂R^(1A), NHSO₂R^(1A), or C(═O)NH₂; andR^(1A) is H or C₁₋₂ alkyl.

In still other embodiments, R³ is H or C(═O)R^(3A), and R^(3A) is C₁₋₃alkyl that includes a C₁₋₃ alkoxy substituent. In certain embodiments,the compound is selected from the group consisting of:

In some embodiments, R³ is SO₂R^(3A), and R^(3A) is optionallysubstituted C₁₋₄ alkyl. In certain embodiments, the compound is selectedfrom the group consisting of:

In any of the embodiments described herein (e.g., a compound of Formula(I) or (II)), the compound is an inhibitor of Sepiapterin Reductase(SPR).

In a related aspect, the invention relates to a pharmaceuticalcomposition that includes any of the compounds (e.g., in an effectiveamount) described herein (e.g., a compound of Formula (I) or (II), orany of Compounds (1)-(39)), or a tautomer, prodrug, or pharmaceuticallyacceptable salt thereof, and a pharmaceutically acceptable excipient.The pharmaceutical composition may include an effective amount of thecompound (e.g., a compound of Formula (I) or (II), or any of Compounds(1)-(39)), or a tautomer, prodrug, or pharmaceutically acceptable saltthereof.

In another related aspect, the invention relates to a method oftreating, reducing, or preventing a condition in a mammal, wherein themethod includes the administration of any of the compounds describedherein (e.g., a compound of Formula (I) or (II), or any of Compounds(1)-(39)), or a tautomer, prodrug, or pharmaceutically acceptable saltthereof, or a pharmaceutical composition thereof, to the mammal in adosage sufficient to inhibit SPR. In one embodiment, the condition ispain. The pain may be neuropathic, inflammatory, nociceptive, orfunctional pain. Further, the pain may be chronic or acute.

Finally, the invention relates to a method of inhibiting SPR in a cell,involving contacting a cell with any of the compounds described herein(e.g., a compound of Formula (I) or (II), or any of Compounds (1)-(39)),or a tautomer, prodrug, or pharmaceutically acceptable salt thereof.

The term “C_(x-y) alkaryl,” as used herein, represents a chemicalsubstituent of formula —RR′, where R is an alkylene group of x to ycarbons and R′ is an aryl group as defined herein. Similarly, by theterm “C_(x-y) alkheteroaryl” is meant a chemical substituent of formula—RR″, where R is an alkylene group of x to y carbons and R″ is aheteroaryl group as defined herein. Other groups preceded by the prefix“alk-” are defined in the same manner. Exemplary unsubstituted alkarylgroups are of from 7 to 16 carbons.

The term “alkcycloalkyl” represents a cycloalkyl group attached to theparent molecular group through an alkylene group.

The terms “alkenyl” or “C₂₋₆ alkenyl,” as used herein, representmonovalent straight or branched chain groups of, unless otherwisespecified, from 2 to 6 carbons containing one or more carbon-carbondouble bonds and is exemplified by ethenyl, 1-propenyl, 2-propenyl,2-methyl-1-propenyl, 1-butenyl, 2-butenyl, and the like. A substitutedC₂₋₆ alkenyl may have, for example, 1, 2, 3, 4, 5, or 6 substituentslocated at any position.

The term “alkheterocyclyl” represents a heterocyclic group attached tothe parent molecular group through an alkylene group. Exemplaryunsubstituted alkheterocyclyl groups are of from 2 to 14 carbons.

The term “alkoxy” represents a chemical substituent of formula —OR,where R is an optionally substituted alkyl group of 1 to 6 carbons,unless otherwise specified (e.g., “C₁₋₃alkoxy” refers to alkoxy groupsincluding a C₁₋₃alkyl group), where the optionally substituted alkyl maybe branched, linear, or cyclic. The C₁₋₆alkyl may be substituted orunsubstituted. A substituted C₁₋₆ alkyl can have, for example, 1, 2, 3,4, 5, or 6 substituents located at any position. Exemplary alkoxy groupsinclude, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy,tert-butoxy, and the like.

The term “alkoxyalkyl” represents an alkyl group that is substitutedwith an alkoxy group. Exemplary unsubstituted alkoxyalkyl groups includebetween 2 to 12 carbons. In some embodiments, the alkyl and the alkoxyeach can be further substituted with 1, 2, 3, or 4 substituent groups asdefined herein for the respective group.

The terms “alkyl” and the prefix “alk-,” as used herein, are inclusiveof both straight chain and branched chain saturated groups of from 1 to6 carbons, unless otherwise specified (e.g., “C₁₋₄alkyl” refers to alkylgroups having 1-4 carbons).

Alkyl groups are exemplified by methyl, ethyl, n- and iso-propyl, n-,sec-, iso- and tert-butyl, neopentyl, and the like, and may beoptionally substituted. Exemplary substituted alkyl groups include, butare not limited to, alkaryl, alkoxyalkyl, aminoalkyl, and haloalkyl(e.g., perfluoroalkyl) groups, as defined herein.

The term “alkylene,” as used herein, represents a saturated divalenthydrocarbon group derived from a straight or branched chain saturatedhydrocarbon by the removal of two hydrogen atoms, and is exemplified bymethylene (—CH₂—), ethylene (—CH₂CH₂—), isopropylene, and the like.

By “amino” is meant a group having a structure —NR′R″, where each R′ andR″ is selected, independently, from H, optionally substituted C₁₋₆alkyl, optionally substituted cycloalkyl, optionally substitutedheterocyclyl, optionally substituted aryl, optionally substitutedheteroaryl, or R′ and R″ combine to form an optionally substitutedheterocyclyl. When R′ is not H or R″ is not H, R′ and R″ may beunsubstituted or substituted with, for example, 1, 2, 3, 4, 5, or 6substituents.

The term “aminoalkyl” or “C₁₋₆alkylamino,” as used herein, represents analkyl group, as defined herein, substituted by an amino group, asdefined herein. The alkyl and amino each can be further substituted with1, 2, 3, or 4 substituent groups as described herein for the respectivegroup.

By “aryl” is meant is an optionally substituted C₆-C₁₀ cyclic group with[4n+2] π electrons in conjugation and where n is 1, 2, or 3.Non-limiting examples of aryls include heteroaryls and, for example,benzene and naphthalene. Aryls also include bi- and tri-cyclic ringsystems in which a non-aromatic saturated or partially unsaturatedcarbocyclic ring (e.g., a cycloalkyl or cycloalkenyl) is fused to anaromatic ring such as benzene or naphthalene. Exemplary aryls fused to anon-aromatic ring include indanyl and tetrahydronaphthyl. Any aryls asdefined herein may be unsubstituted or substituted. A substituted arylmay be optionally substituted with, for example, 1, 2, 3, 4, 5, or 6substituents located at any position of the ring.

By “cycloalkyl” is meant an optionally substituted, saturated orpartially unsaturated 3- to 10-membered monocyclic or polycyclic (e.g.,bicyclic, or tricyclic) hydrocarbon ring system. Where a cycloalkyl ispolycyclic, the constituent cycloalkyl rings may be fused together, forma spirocyclic structure, or the polycyclic cycloalkyl may be a bridgedcycloalkyl (e.g., adamantyl or norbonanyl). Exemplary cycloalkylsinclude cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, andcycloheptyl. Cycloalkyls may be unsubstituted or substituted. Asubstituted cycloalkyl can have, for example, 1, 2, 3, 4, 5, or 6substituents.

The term “cycloalkyl,” as used herein represents a monovalent saturatedor unsaturated non-aromatic cyclic hydrocarbon group of from three toeight carbons, unless otherwise specified, and is exemplified bycyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,bicyclo[2.2.1.]heptyl and the like. The cycloalkyl groups of thisinvention can be optionally substituted

The term an “effective amount” of a compound (e.g., any of Compounds(1)-(39) or a compound according to Formula (I) or (II)), as usedherein, is that amount sufficient to effect beneficial or desiredresults, such as clinical results, and, as such, an “effective amount”depends upon the context in which it is being applied. For example, inthe context of administering an agent that inhibits SPR, an effectiveamount of an agent is, for example, an amount sufficient to achieve areduction in SPR activity as compared to the response obtained withoutadministration of the agent and thereby prevents, reduces, or eliminatesthe sensation of pain. The effective amount of active compound(s) usedto practice the present invention for therapeutic treatment of pain alsovaries depending upon the manner of administration, the age, and bodyweight, of the subject as well as the underlying pathology that iscausing the pain. Ultimately, the attending physician or veterinarianwill decide the appropriate amount and dosage regimen.

The term “haloalkyl,” as used herein, represents an alkyl group, asdefined herein, substituted by a halogen group (i.e., F, Cl, Br, or I).A haloalkyl may be substituted with one, two, three, or, in the case ofalkyl groups of two carbons or more, four halogens. In some embodiments,the haloalkyl group can be further substituted with 1, 2, 3, or 4substituent groups as described herein for alkyl groups. Haloalkylgroups include perfluoroalkyls.

By “halogen” or “halo” is meant fluorine (—F), chlorine (—Cl), bromine(—Br), or iodine (—I).

The term “heteroaryl,” as used herein, represents that subset ofheterocycles, as defined herein, which are aromatic: i.e., they contain4n+2 pi electrons within the mono- or multicyclic ring system. Exemplaryheteroaryls include, but are not limited to, furan, thiophene, pyrrole,thiadiazole (e.g., 1,2,3-thiadiazole or 1,2,4-thiadiazole), oxadiazole(e.g., 1,2,3-oxadiazole or 1,2,5-oxadiazole), oxazole, benzoxazole,isoxazole, isothiazole, pyrazole, thiazole, benzthiazole, triazole(e.g., 1,2,4-triazole or 1,2,3-triazole), benzotriazole, pyridines,pyrimidines, pyrazines, quinoline, isoquinoline, purine, pyrazine,pteridine, triazine (e.g, 1,2,3-triazine, 1,2,4-triazine, or1,3,5-triazine)indoles, 1,2,4,5-tetrazine, benzo[b]thiophene,benzo[c]thiophene, benzofuran, isobenzofuran, and benzimidazole.Heteroaryls may be unsubstituted or substituted. Substituted heteroarylscan have, for example, 1, 2, 3, 4, 5, or 6 substituents.

The terms “heterocycle” or “heterocyclyl,” as used interchangeablyherein represent a 5-, 6- or 7-membered ring, unless otherwisespecified, containing one, two, three, or four heteroatoms independentlyselected from the group consisting of nitrogen, oxygen and sulfur. The5-membered ring has zero to two double bonds and the 6- and 7-memberedrings have zero to three double bonds. The term “heterocyclyl” alsorepresents a heterocyclic compound having a bridged multicyclicstructure in which one or more carbons and/or heteroatoms bridges twonon-adjacent members of a monocyclic ring, e.g., a quinuclidinyl group.The term “heterocycle” includes bicyclic, tricyclic and tetracyclicgroups in which any of the above heterocyclic rings is fused to one,two, or three rings, e.g., an aryl ring, a cyclohexane ring, acyclohexene ring, a cyclopentane ring, a cyclopentene ring and anothermonocyclic heterocyclic ring, such as indolyl, quinolyl, isoquinolyl,tetrahydroquinolyl, benzofuryl, benzothienyl and the like. Examples offused heterocycles include tropanes and1,2,3,5,8,8a-hexahydroindolizine. Heterocyclics include pyrrolyl,pyrrolinyl, pyrrolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl,imidazolyl, imidazolinyl, imidazolidinyl, pyridyl, piperidinyl,homopiperidinyl, pyrazinyl, piperazinyl, pyrimidinyl, pyridazinyl,oxazolyl, oxazolidinyl, isoxazolyl, isoxazolidinyl, morpholinyl,thiomorpholinyl, thiazolyl, thiazolidinyl, isothiazolyl,isothiazolidinyl, indolyl, quinolinyl, isoquinolinyl, benzimidazolyl,benzothiazolyl, benzoxazolyl, furyl, thienyl, thiazolidinyl,isothiazolyl, isoindazoyl, triazolyl, tetrazolyl, oxadiazolyl, uricyl,thiadiazolyl, pyrimidyl, tetrahydrofuranyl, dihydrofuranyl,tetrahydrothienyl, dihydrothienyl, dihydroindolyl, tetrahydroquinolyl,tetrahydroisoquinolyl, pyranyl, dihydropyranyl, dithiazolyl,benzofuranyl, benzothienyl and the like. Any of the heterocycle groupsmentioned herein may be optionally substituted with one, two, three,four or five substituents

The term “hydroxyl,” as used herein, represents an —OH group.

The term “nitrile,” as used herein, represents a —CN group.

By “pain” is meant all types of pain including inflammatory pain,nociceptive pain, functional pain, and neuropathic pain (peripheral andcentral), whether acute or chronic. Exemplary, non-limiting types ofpain that can be treated according to the methods described hereininclude musculo-skeletal pain (after trauma, infections, and exercise),neuropathic pain caused by spinal cord injury, tumors, compression,inflammation, dental pain, episiotomy pain, deep and visceral pain(e.g., heart pain, bladder pain, or pelvic organ pain), muscle pain, eyepain, orofacial pain (e.g., odontalgia, trigeminal neuralgia,glossopharyngeal neuralgia), abdominal pain, gynecological pain (e.g.,dysmenorrhea and labor pain), pain associated with nerve and root damagedue to trauma, compression, inflammation, toxic chemicals, metabolicdisorders, hereditary conditions, infections, vasculitis and autoimmunediseases, central nervous system pain, such as pain due to spinal cordor brain stem damage, cerebrovascular accidents, tumors, infections,demyelinating diseases including multiple sclerosis, low back pain,sciatica, and post-operative pain. Pain can also be associated withconditions that include, for example, soft tissue, joint, boneinflammation and/or damage (e.g., acute trauma, osteoarthritis, orrheumatoid arthritis), myofascial pain syndromes (fibromyalgia),headaches (including cluster headache, migraine, and tension typeheadache), myocardial infarction, angina, ischemic cardiovasculardisease, post-stroke pain, sickle cell anemia, peripheral vascularocclusive disease, cancer, inflammatory conditions of the skin orjoints, diabetic neuropathy, and acute tissue damage from surgery ortraumatic injury (e.g., burns, lacerations, or fractures).

The term “perfluoroalkyl,” as used herein, represents an alkyl group, asdefined herein, where each hydrogen radical bound to the alkyl group hasbeen replaced by a fluoride radical. Perfluoroalkyl groups areexemplified by trifluoromethyl, pentafluoroethyl, and the like.

The term “pharmaceutical composition,” as used herein, represents acomposition containing a compound (e.g., an effective amount of thecompound) described herein (e.g., any of Compounds (1)-(39) or acompound according to Formula (I) or (II)), formulated with apharmaceutically acceptable excipient, and typically manufactured orsold with the approval of a governmental regulatory agency as part of atherapeutic regimen for the treatment of disease in a mammal.Pharmaceutical compositions can be formulated, for example, for oraladministration in unit dosage form (e.g., a tablet, capsule, caplet,gelcap, or syrup); for topical administration (e.g., as a cream, gel,lotion, or ointment); for intravenous administration (e.g., as a sterilesolution free of particulate emboli and in a solvent system suitable forintravenous use); or in any other formulation described herein.

A “pharmaceutically acceptable excipient,” as used herein, refers anyingredient other than the compounds described herein (for example, avehicle capable of suspending or dissolving the active compound) andhaving the properties of being nontoxic and non-inflammatory in apatient. Excipients may include, for example: antiadherents,antioxidants, binders, coatings, compression aids, disintegrants, dyes(colors), emollients, emulsifiers, fillers (diluents), film formers orcoatings, flavors, fragrances, glidants (flow enhancers), lubricants,preservatives, printing inks, sorbents, suspending or dispersing agents,sweeteners, or waters of hydration. Exemplary excipients include, butare not limited to: butylated hydroxytoluene (BHT), calcium carbonate,calcium phosphate (dibasic), calcium stearate, croscarmellose,crosslinked polyvinyl pyrrolidone, citric acid, crospovidone, cysteine,ethylcellulose, gelatin, hydroxypropyl cellulose, hydroxypropylmethylcellulose, lactose, magnesium stearate, maltitol, mannitol,methionine, methylcellulose, methyl paraben, microcrystalline cellulose,polyethylene glycol, polyvinyl pyrrolidone, povidone, pregelatinizedstarch, propyl paraben, retinyl palmitate, shellac, silicon dioxide,sodium carboxymethyl cellulose, sodium citrate, sodium starch glycolate,sorbitol, starch (corn), stearic acid, stearic acid, sucrose, talc,titanium dioxide, vitamin A, vitamin E, vitamin C, and xylitol.

The term “pharmaceutically acceptable prodrugs” as used herein,represents those prodrugs of the compounds of the present inventionwhich are, within the scope of sound medical judgment, suitable for usein contact with the tissues of humans and animals with undue toxicity,irritation, allergic response, and the like, commensurate with areasonable benefit/risk ratio, and effective for their intended use, aswell as the zwitterionic forms, where possible, of the compounds of theinvention.

The term “pharmaceutically acceptable salt,” as used herein, representsthose salts which are, within the scope of sound medical judgment,suitable for use in contact with the tissues of humans and animalswithout undue toxicity, irritation, allergic response and the like andare commensurate with a reasonable benefit/risk ratio. Pharmaceuticallyacceptable salts are well known in the art. For example,pharmaceutically acceptable salts are described in: Berge et al., J.Pharmaceutical Sciences 66:1-19, 1977 and in Pharmaceutical Salts:Properties, Selection, and Use, (Eds. P. H. Stahl and C. G. Wermuth),Wiley-VCH, 2008. The salts can be prepared in situ during the finalisolation and purification of the compounds of the invention orseparately by reacting the free base group with a suitable organic acid.Representative acid addition salts include acetate, adipate, alginate,ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate,butyrate, camphorate, camphersulfonate, citrate, cyclopentanepropionate,digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate,glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide,hydrochloride, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate,lactate, laurate, lauryl sulfate, malate, maleate, malonate,methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate,oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate,phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate,tartrate, thiocyanate, toluenesulfonate, undecanoate, valerate salts andthe like. Representative alkali or alkaline earth metal salts includesodium, lithium, potassium, calcium, magnesium and the like, as well asnontoxic ammonium, quaternary ammonium, and amine cations, including,but not limited to ammonium, tetramethylammonium, tetraethylammonium,methylamine, dimethylamine, trimethylamine, triethylamine, ethylamineand the like.

The terms “pharmaceutically acceptable solvate” or “solvate,” as usedherein, means a compound of the invention wherein molecules of asuitable solvent are incorporated in the crystal lattice. A suitablesolvent is physiologically tolerable at the dosage administered. Forexample, solvates may be prepared by crystallization, recrystallization,or precipitation from a solution that includes organic solvents, water,or a mixture thereof. Examples of suitable solvents are ethanol, water(for example, mono-, di-, and tri-hydrates), N-methylpyrrolidinone(NMP), dimethyl sulfoxide (DMSO), N,N′-dimethylformamide (DMF),N,N′-dimethylacetamide (DMAC), 1,3-dimethyl-2-imidazolidinone (DMEU),1,3-dimethyl-3,4,5,6-tetrahydro-2-(1H)-pyrimidinone (DMPU), acetonitrile(ACN), propylene glycol, ethyl acetate, benzyl alcohol, 2-pyrrolidone,benzyl benzoate, and the like. When water is the solvent, the solvate isreferred to as a “hydrate.”

The term “prevent,” as used herein, refers to prophylactic treatment ortreatment that prevents one or more symptoms or conditions of a disease,disorder, or conditions described herein such as pain (e.g. neuropathicor inflammatory pain). Preventative treatment can be initiated, forexample, prior to (“pre-exposure prophylaxis”) or following(“post-exposure prophylaxis”) an event that precedes the onset of thedisease, disorder, or conditions. Preventive treatment that includesadministration of a compound of the invention, or a pharmaceuticalcomposition thereof, can be acute, short-term, or chronic. The dosesadministered may be varied during the course of preventative treatment.

The term “prodrug,” as used herein, represents compounds which arerapidly transformed in vivo to the parent compound of the above formula(e.g., any of Compounds (1)-(39) or a compound according to Formula (I)or (II)), for example, by hydrolysis in blood. Prodrugs of the compoundsof the invention may be conventional esters. Some common esters whichhave been utilized as prodrugs are phenyl esters, aliphatic (C₇-C₈ orC₈-C₂₄) esters, cholesterol esters, acyloxymethyl esters, carbamates,and amino acid esters. For example, a compound of the invention thatcontains an OH group may be acylated at this position in its prodrugform. A thorough discussion is provided in T. Higuchi and V. Stella,Pro-drugs as Novel Delivery Systems, Vol. 14 of the A.C.S. SymposiumSeries, Edward B. Roche, ed., Bioreversible Carriers in Drug Design,American Pharmaceutical Association and Pergamon Press, 1987, andJudkins et al., Synthetic Communications 26(23):4351-4367, 1996, each ofwhich is incorporated herein by reference. Preferably, prodrugs of thecompounds of the present invention are pharmaceutically acceptable.

The term “thioether,” as used herein, refers to a C—SR group, where R isan unsubstituted alkyl or a substituted alkyl (e.g., an alkaryl groupthat may be further substituted) as described herein.

The term “thiol,” as used herein, refers to the —SH group.

The term “thiooxo,” as used herein, refers to a C═S group, where acarbon atom is double-bonded to sulfur.

As used herein, and as well understood in the art, “treatment” is anapproach for obtaining beneficial or desired results, such as clinicalresults. Beneficial or desired results can include, but are not limitedto, alleviation or amelioration of one or more symptoms or conditions;diminishment of extent of disease, disorder, or condition; stabilized(i.e. not worsening) state of disease, disorder, or condition;preventing spread of disease, disorder, or condition; delay or slowingthe progress of the disease, disorder, or condition; amelioration orpalliation of the disease, disorder, or condition; and remission(whether partial or total), whether detectable or undetectable.“Palliating” a disease, disorder, or condition means that the extentand/or undesirable clinical manifestations of the disease, disorder, orcondition are lessened and/or time course of the progression is slowedor lengthened, as compared to the extent or time course in the absenceof treatment. As compared with an equivalent untreated control, such areduction of pain is at least a 5%, 10%, 20%, 40%, 50%, 60%, 80%, 90%,95%, or 100% reduction as measured by any standard technique known inthe art. To treat pain, according to the methods of this invention, thetreatment does not necessarily provide therapy for the underlyingpathology that is causing the painful sensation. Treatment of pain canbe purely symptomatic.

Any of the groups described herein can be substituted or unsubstituted.Where a group is substituted, the group may be substituted with 1, 2, 3,4, 5, or 6 substituents. Optional substituents include, but are notlimited to: C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, cycloalkyl,cycloalkenyl, heterocyclyl, aryl, heteroaryl, halogen; azido(—N₃), nitro(—NO₂), cyano (—CN), acyloxy(—OC(═O)R′), acyl (—C(═O)R′), alkoxy (—OR′),amido (—NR′C(═O)R″ or —C(═O)NRR′), amino (—NRR′), carboxylic acid(—CO₂H), carboxylic ester (—CO₂R′), carbamoyl (—OC(═O)NR′R″ or—NRC(═O)OR′), hydroxy (—OH), isocyano (—NC), sulfonate (—S(═O)₂OR),sulfonamide (—S(═O)₂NRR′ or —NRS(═O)₂R), or sulfonyl (—S(═O)₂R), whereeach R or R′ is selected, independently, from H, C₁₋₆ alkyl, C₂₋₆alkenyl, C₂₋₆ alkynyl, cycloalkyl, heterocyclyl, aryl, or heteroaryl. Asubstituted group may have, for example, 1, 2, 3, 4, 5, 6, 7, 8, or 9substituents. In some embodiments, each hydrogen in a group may bereplaced by a substituent group (e.g., perhaloalkyl groups such as —CF₃or —CF₂CF₃ or perhaloaryls such as —C₆F₅). In other embodiments, asubstituent group may itself be further substituted by replacing ahydrogen of the substituent group with another substituent group such asthose described herein. Substituents may be further substituted with,for example, 1, 2, 3, 4, 5, or 6 substituents as defined herein. Forexample, a lower C₁₋₆ alkyl or an aryl substituent group (e.g.,heteroaryl, phenyl, or naphthyl) may be further substituted with 1, 2,3, 4, 5, or 6 substituents as described herein.

Asymmetric or chiral centers may exist in any of the compounds of thepresent invention. The present invention contemplates the variousstereoisomers and mixtures thereof. Individual stereoisomers ofcompounds of the present invention are prepared synthetically fromcommercially available starting materials that contain asymmetric orchiral centers or by preparation of mixtures of enantiomeric compoundsfollowed by resolution well-known to those of ordinary skill in the art.These methods of resolution are exemplified by (1) attachment of aracemic mixture of enantiomers, designated (+/−), to a chiral auxiliary,separation of the resulting diastereomers by recrystallization orchromatography and liberation of the optically pure product from theauxiliary or (2) direct separation of the mixture of optical enantiomerson chiral chromatographic columns. Alternatively, chiral compounds canbe prepared by an asymmetric synthesis that favors the preparation ofone enantiomer over the other. Alternatively a chiral pool synthesis(starting with an enantiomerically pure building block) can be usedwherein the chiral group or center is retained in the intermediate orfinal product. Enantiomers are designated herein by the symbols “R,” or“S,” depending on the configuration of substituents around the chiralatom. Alternatively, enantiomers are designated as (+) or (−) dependingon whether a solution of the enantiomer rotates the plane of polarizedlight clockwise or counterclockwise, respectively. In other cases,diastereomeric isomers such as cis and trans isomers may be separated bycolumn chromatography, chiral chromatography, or recrystallization. Insome cases, derivatization can improve the separation of these mixtures.

Geometric isomers may also exist in the compounds of the presentinvention. The present invention contemplates the various geometricisomers and mixtures thereof resulting from the arrangement ofsubstituents around a carbon-carbon double bond and designates suchisomers as of the Z or E configuration. It is also recognized that forstructures in which tautomeric forms are possible, the description ofone tautomeric form is equivalent to the description of both, unlessotherwise specified.

It is understood that substituents and substitution patterns on thecompounds of the invention can be selected by one of ordinary skill inthe art to provide compounds that are chemically stable and that can bereadily synthesized by techniques known in the art, as well as thosemethods set forth below, from readily available starting materials. If asubstituent is itself substituted with more than one group, it isunderstood that these multiple groups may be on the same carbon or ondifferent carbons, so long as a stable structure results.

Other features and advantages of the invention will be apparent from thefollowing Detailed Description, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic of BH4 biosynthesis and control. BH4 issynthesized de novo from guanosine triphosphate (GTP) in three stepsmediated by GTP cyclohydrolase (GCH-1), 6-pyruvoyltetrahydriobiopterinsynthase (PTPS), and sepiapterin reductase (SPR). BH4 is also generatedby a separate recycling pathway that converts quinoid BH4 or BH2 to BH4via enzymatic reduction.

DETAILED DESCRIPTION

In general, the invention relates to compounds according to Formulas (I)and (II), or a tautomer, prodrug, or pharmaceutically acceptable saltthereof, or a pharmaceutical composition thereof, and the use of thesecompounds and compositions in methods of treatment or to inhibitsepiapterin reductase (SPR).

Compounds of Formula (I) have the following structure

or a tautomer, prodrug, or pharmaceutically acceptable salt thereof,where

each of X¹ and X² is, independently, N, C—H, or C-halogen;

A is a single bond, C(═O), or SO₂;

R¹ is (CH₂)_(n)OR^(1A), halogen (e.g., F, Cl, Br, or I, preferably Cl),amino (e.g., NH₂), CN, SO₂R^(1A), NHSO₂R^(1A), NHC(═O)R^(1A), orC(═O)N(R^(1A))₂;

each R^(1A) is, independently, H or optionally substituted C₁₋₆ alkyl; nis 0, 1, or 2;

R² is CH₂OR^(2A), optionally substituted C₁₋₆ alkyl, optionallysubstituted C₃₋₉ cycloalkyl, optionally substituted aryl, optionallysubstituted heterocyclyl, or optionally substituted heteroaryl;

R^(2A) is H or optionally substituted C₁₋₆ alkyl;

R^(3A) and R^(3B) are both II, or R^(3A) and R^(3B) combine to form ═O;

R^(4A) and R^(4B) are both H, or R^(4A) and R^(4B) combine to form ═O;

each of R⁵ and R⁶ is, independently, H, optionally substituted C₁₋₆alkyl, optionally substituted C₃₋₁₀ cycloalkyl, optionally substitutedalkaryl, or optionally substituted alkheteroaryl; and

where when A is C(═O), R¹ is OH, R² is CH₂OMe, R^(3A), R^(3B), R^(4A),and R^(4B) are each H, and R⁵ is H, R⁶ is not H.

In some embodiments, one and only one of R^(3A) and R^(3B) and R^(4A)and R^(4B) can combine to form ═O.

Compounds of Formula (II) have the following structure:

or a tautomer, prodrug, or pharmaceutically acceptable salt thereof,where

X is N or CH;

m is 0 or 1;

R¹ is (CH₂)_(n)OR^(1A), halogen, CN, amino, SO₂R^(1A), NHSO₂R^(1A),NHC(═O)R^(1A), or C(═O)N(R^(1A))₂;

each R^(1A) is, independently, H or optionally substituted C₁₋₆ alkyl;

n is 0, 1, or 2;

R² is H or optionally substituted C₁₋₃ alkyl;

R³ is H, C(═O)R^(3A), or SO₂R^(3A); and

R^(3A) is optionally substituted C₁₋₆ alkyl.

Exemplary compounds of the invention, or a tautomer, prodrug, orpharmaceutically acceptable salt thereof, include those shown in Table1.

TABLE 1 No. Structure  (1)

 (2)

 (3)

 (4)

 (5)

 (6)

 (7)

 (8)

 (9)

(10)

(11)

(12)

(13)

(14)

(15)

(16)

(17)

(18)

(19)

(20)

(21)

(22)

(23)

(24)

(25)

(26)

(27)

(28)

(29)

(30)

(31)

(32)

(33)

(34)

(35)

(36)

(37)

(38)

(39)

Synthesis

The compounds described herein, e.g., any of Compounds (1)-(39) or acompound according to Formula (I) or (II), can be prepared according tomethods known in the art. Exemplary methods include the following.

Synthesis Of Formula (I) Compounds

Compounds of Formula (I) can be synthesized by treating various2-(1H-indol-3-yl)ethanamine starting materials with electrophiles asshown in Scheme 1.

In this scheme, R²-A-LG is an electrophilic reagent, where R² and A areas defined for Formula (I) and LG is a leaving group. Suitable R²-A-LGreagents include, but are not limited to, alkyl halides, alkylsulfonates, acyl chlorides, carbonates, acyl anhydrides, and sulfonylchlorides. Further exemplary reagents are described in the syntheticexamples provided herein. In some embodiments, e.g., when R¹ is OH, itmay be desirable to selectively deprotect this group (e.g., deacylateany acyl esters that may have formed). Such transformations can beaccomplished using methods known in the art, e.g., deprotection underbasic conditions, or those described in Greene, Protective Groups InOrganic Synthesis, 3^(rd) Edition (John Wiley & Sons, New York, 1999),which is incorporated herein by reference.

Compounds of Formula (I) can also be prepared from other indole startingmaterials, as shown in Scheme 2.

Using Route A, an indole compound can be elaborated to the corresponding3-carboxamido intermediate (see, for example, the synthetic protocolsfor Compounds (10)-(12)). If desired, the carbonyl can be treated underreducing conditions to afford a saturated linking group.

When R¹ is an electron-withdrawing group, Route B can be used.Accordingly, the indole starting material is olefinated to form thecorresponding nitro-alkene intermediate. Reduction of the nitro group toan amino group followed by treatment with an electrophile R²-A-LG, asdescribed for Scheme 1, can afford still other compounds of Formula (I).If desired, the indole compound can be N-alkylated using anelectrophilic reagent such as R⁶-LG, where R⁶ is as defined for Formula(I) and LG is a leaving group.

Compounds of Formula (I) can also be prepared by the cyclization ofarylhydrazine starting materials as shown in Scheme 3 (see, for example,the synthesis of Compound (17)).

Synthesis Of Formula (II) Compounds

Compounds of Formula (II) can be prepared by the treatment ofphenethylamino starting materials with electrophilic RLG reagents, asshown in Scheme 4.

In Scheme 4, R can be any of the R² or R³ groups described for Formula(II), and LG is a leaving group. If a tertiary amine is desired, thenumber of equivalents of RLG can be adjusted accordingly.

If the required phenethylamino starting material is not commerciallyavailable, the required compounds can be prepared from the correspondingphenylcarboxaldehyde via olefination to the corresponding nitroalkeneand reduction to form the desired phenethylamino compound (Scheme 5).

Compounds of Formula (II) can also be prepared using carboxylic acidstarting materials, as shown in Scheme 6.

In Scheme 6, Ar represents an aryl group, e.g., phenyl, and Hetrepresents a heteroaryl group, e.g., pyridyl. In this scheme, thecarboxylic acid group is transformed to a chloromethyl group. Treatmentof this intermediate with cyanide followed by reduction affords thedesired amine compound. If required, the amine compound can be treatedwith an electrophile RLG to afford still other compounds of Formula(II).Pharmaceutical Compositions

The compounds of the invention (e.g., any of Compounds (1)-(39) or acompound according to Formula (I) or (II)), or tautomers, salts,solvates, or prodrugs thereof, are preferably formulated intopharmaceutical compositions for administration to human subjects in abiologically compatible form suitable for administration in vivo.Accordingly, in another aspect, the present invention provides apharmaceutical composition that includes a compound of the invention, ora tautomer, salt, solvate, or prodrug thereof, in admixture with asuitable diluent, carrier, or excipient.

The compounds of the invention (e.g., any of Compounds (1)-(39) or acompound according to Formula (I) or (II)) may be used in the form ofthe free base, in the form of tautomers, salts, solvates, prodrugs, orpharmaceutical compositions. All forms are within the scope of theinvention. In accordance with the methods of the invention, thedescribed compounds, or tautomers, salts, solvates, prodrugs, orpharmaceutical compositions thereof, may be administered to a patient ina variety of forms depending on the selected route of administration, aswill be understood by those skilled in the art. The compounds of theinvention, or tautomers, salts, solvates, prodrugs, or pharmaceuticalcompositions thereof, may be administered, for example, by oral,parenteral, buccal, sublingual, nasal, rectal, patch, pump, ortransdermal administration and the pharmaceutical compositionsformulated accordingly. Parenteral administration includes intravenous,intraperitoneal, subcutaneous, intramuscular, transepithelial, nasal,intrapulmonary, intrathecal, rectal, and topical modes ofadministration. Parenteral administration may be by continuous infusionover a selected period of time.

A compound of the invention (e.g., any of Compounds (1)-(39) or acompound according to Formula (I) or (II)), or a tautomer, salt,solvate, or prodrug thereof, may be orally administered, for example,with an inert diluent or with an assimilable edible carrier, or it maybe enclosed in hard or soft shell gelatin capsules, or it may becompressed into tablets, or it may be incorporated directly with thefood of the diet. For oral therapeutic administration, a compound of theinvention, or a tautomer, salt, solvate, or prodrug thereof, may beincorporated with an excipient and used in the form of ingestibletablets, buccal tablets, troches, capsules, elixirs, suspensions,syrups, wafers, and the like.

A compound of the invention (e.g., any of Compounds (1)-(39) or acompound according to Formula (I) or (II)), or a tautomer, salt,solvate, or prodrug thereof, may also be administered parenterally.Solutions of a compound of the invention can be prepared in watersuitably mixed with a surfactant, such as hydroxypropylcellulose.Dispersions can also be prepared in glycerol, liquid polyethyleneglycols, DMSO and mixtures thereof with or without alcohol, and in oils.Under ordinary conditions of storage and use, these preparations maycontain a preservative to prevent the growth of microorganisms.Conventional procedures and ingredients for the selection andpreparation of suitable formulations are described, for example, inRemington's Pharmaceutical Sciences (2003-20th edition) and in TheUnited States Pharmacopeia: The National Formulary (USP 32-NF 27),published in 2008.

The pharmaceutical forms suitable for injectable use include sterileaqueous solutions or dispersions and sterile powders for theextemporaneous preparation of sterile injectable solutions ordispersions. In all cases the form must be sterile and must be fluid tothe extent that may be easily administered via syringe.

Pharmaceutical compositions for nasal administration may conveniently beformulated as aerosols, drops, gels, and powders. Aerosol formulationstypically include a solution or fine suspension of the active substancein a physiologically acceptable aqueous or non-aqueous solvent and areusually presented in single or multidose quantities in sterile form in asealed container, which can take the form of a cartridge or refill foruse with an atomizing device. Alternatively, the sealed container may bea unitary dispensing device, such as a single dose nasal inhaler or anaerosol dispenser fitted with a metering valve which is intended fordisposal after use. Where the dosage form comprises an aerosoldispenser, it will contain a propellant, which can be a compressed gas,such as compressed air or an organic propellant, such asfluorochlorohydrocarbon. The aerosol dosage forms can also take the formof a pump-atomizer.

Compositions suitable for buccal or sublingual administration includetablets, lozenges, and pastilles, where the active ingredient isformulated with a carrier, such as sugar, acacia, tragacanth, or gelatinand glycerine. Compositions for rectal administration are convenientlyin the form of suppositories containing a conventional suppository base,such as cocoa butter.

The compounds of the invention may be administered to an animal, e.g., ahuman, alone or in combination with pharmaceutically acceptablecarriers, as noted above, the proportion of which is determined by thesolubility and chemical nature of the compound, chosen route ofadministration, and standard pharmaceutical practice.

The dosage of the compounds of the invention, and/or compositionscomprising a compound of the invention, can vary depending on manyfactors, such as the pharmacodynamic properties of the compound; themode of administration; the age, health, and weight of the recipient;the nature and extent of the symptoms; the frequency of the treatment,and the type of concurrent treatment, if any; and the clearance rate ofthe compound in the animal to be treated.

One of skill in the art can determine the appropriate dosage based onthe above factors. The compounds of the invention may be administeredinitially in a suitable dosage that may be adjusted as required,depending on the clinical response. Generally, dosage levels of between0.1 μg/kg to 100 mg/kg of body weight are administered daily as a singledose or divided into multiple doses. Desirably, the general dosage rangeis between 250 μg/kg to 5.0 mg/kg of body weight per day. Widevariations in the needed dosage are to be expected in view of thediffering efficiencies of the various routes of administration. Forinstance, oral administration generally would be expected to requirehigher dosage levels than administration by intravenous injection.Variations in these dosage levels can be adjusted using standardempirical routines for optimization, which are well known in the art. Ingeneral, the precise therapeutically effective dosage will be determinedby the attending physician in consideration of the above identifiedfactors.

Kits

Any of the compounds or pharmaceutical compositions of the invention(e.g., any of Compounds (1)-(39) or a compound according to Formula (I)or (II)) can be used together with a set of instructions, i.e., to forma kit. The kit may include instructions for use of the compounds of theinvention in a screening method or as a therapy as described herein. Forexample, the instructions may provide dosing and therapeutic regimes foruse of the compounds of the invention to reduce pain, including any typeof pain described herein.

Inhibitors of SPR

The compounds and compositions described herein can be used to inhibitSPR, which catalyzes the final step of the transformation of GTP to BH4.BH4 is an essential co-factor required for normal function of severalenzyme and neurotransmitter systems: phenylalanine hydroxylase, tyrosinehydroxylase, tryptophan hydroxylase, and the 3 nitric oxide synthases(NOS) subtypes all rely on BH4 allosteric regulation (Thony et al.,Biochem. J. 347:1-16, 2000). BH4 is synthesized from guanosinetriphosphate (GTP) in three tightly regulated steps byGCH-1,6-pyruvoyltetrahydriobiopterin synthase (PTPS), and sepiapterinreductase (SPR) (FIG. 1). The final step in the BH4 synthetic pathway isthe conversion of 6-pyruvoyl tetrahydropterin to BH4 by sepiapterinreductase (SPR).

Two of the enzymes involved in de novo BH4 synthesis, GCH-1 and SPR, areup-regulated in preclinical pain models, and reducing the activity ofthese enzymes leads to preclinical pain relief (Tegeder et al., NatureMedicine 12:1269-1277, 2006). Accordingly, agents that reduce de novoBH4 synthesis (e.g., via direct active site inhibition of SPR) can beused in the prevention or treatment of pain.

Initial studies demonstrated that SPR is weakly inhibited bycatecholamines and indoleamines, suggesting a negative feedbackmechanism by downstream biogenic amines (Katoh et al., Biochem. Biophys.Res. Commun. 105:75-81, 1982; Smith et al., J. Biol. Chem.267:5509-5607, 1992). Additional structural information can be obtainedby analysis of the SPR protein structure. The crystal structures ofhuman, mouse, and Chlorobium tepidum SPR have been solved in complexwith a range of active site ligands including N-acetyl serotonin, NADPH,NADPH+, oxaloacctate and sepiapterin. The first solved structure ofmouse SPR reveals a homodimeric structure of 261 amino acids (Auerbachet al., EMBO J. 16:7219-7230, 1997). The liganded protein X-ray crystalstructure complexes of SPR reveal an active site formed by a 15 Å-deeppocket surrounded by the hydrophobic residues Leu105, Leu159, Tyr165,Trp168, Tyr171, Met206 and Cys160. SPR is a homolog of otheroxidoreductase drug targets such as the M.tb InhA, the target ofanti-tuberculosis drug isoniazid. The inhibition of SPR can be a usefultarget for developing new methods for the treatment or prevention ofpain.

Inhibitors of SPR can be identified according to the methods describedherein or known in the art (e.g., Katoh et al., Biochem. Biophys. Res.Commun. 105:75-81, 1982; Smith et al., J. Biol. Chem. 267:5509-5607,1992).

Although not necessary, if desired, candidate SPR inhibitors can betested for efficacy in any standard animal model of pain. Various modelstest the sensitivity of normal animals to intense or noxious stimuli(physiological or nociceptive pain). These tests include responses tothermal, mechanical, or chemical stimuli. Thermal stimuli usuallyinvolve the application of hot stimuli (typically varying between 42-55°C.) including, for example: radiant heat to the tail (the tail flicktest), radiant heat to the plantar surface of the hindpaw (theHargreaves test), the hotplate test, and immersion of the hindpaw ortail into hot water. Immersion in cold water, acetone evaporation, orcold plate tests may also be used to test cold pain responsiveness.Tests involving mechanical stimuli typically measure the threshold foreliciting a withdrawal reflex of the hindpaw to graded strengthmonofilament von Frey hairs or to a sustained pressure stimulus to a paw(e.g., the Ugo Basile analgesiometer). The duration of a response to astandard pinprick may also be measured. When using a chemical stimulus,the response to the application or injection of a chemical irritant(e.g., capsaicin, mustard oil, bradykinin, ATP, formalin, acetic acid)to the skin, muscle joints or internal organs (e.g., bladder orperitoneum) is measured.

In addition, various tests assess pain sensitization by measuringchanges in the excitability of the peripheral or central components ofthe pain neural pathway. In this regard, peripheral sensitization (i.e.,changes in the threshold and responsiveness of high thresholdnociceptors) can be induced by repeated heat stimuli as well as theapplication or injection of sensitizing chemicals (e.g., prostaglandins,bradykinin, histamine, serotonin, capsaicin, or mustard oil). Centralsensitization (i.e., changes in the excitability of neurons in thecentral nervous system induced by activity in peripheral pain fibers)can be induced by noxious stimuli (e.g., heat), chemical stimuli (e.g.,injection or application of chemical irritants), or electricalactivation of sensory fibers.

Various pain tests developed to measure the effect of peripheralinflammation on pain sensitivity can also be used, if desired, toconfirm the efficacy of SPR inhibitors (Stein et al., Pharmacol.Biochem. Behav. (1988) 31: 445-451; Woolf et al., Neurosci. (1994) 62:327-331). Additionally, various tests assess peripheral neuropathic painusing lesions of the peripheral nervous system. One such example is the“axotomy pain model” (Watson, J. Physiol. (1973) 231:41). Other similartests include the SNL test which involves the ligation of a spinalsegmental nerve (Kim and Chung Pain (1992) 50: 355), the Seltzer modelinvolving partial nerve injury (Seltzer, Pain (1990) 43: 205-18), thespared nerve injury (SNI) model (Decosterd and Woolf, Pain (2000)87:149), chronic constriction injury (CCl) model (Bennett (1993) MuscleNerve 16: 1040), tests involving toxic neuropathies such as diabetes(streptozocin model), pyridoxine neuropathy, taxol, vincristine, andother antineoplastic agent-induced neuropathies, tests involvingischaemia to a nerve, peripheral neuritis models (e.g., CFA appliedperi-neurally), models of post-herpetic neuralgia using HSV infection,and compression models.

In all of the above tests, outcome measures may be assessed, forexample, according to behavior, electrophysiology, neurochemistry, orimaging techniques to detect changes in neural activity. Furthermore,several pain tests that mimic central neuropathic pain involve lesionsof the central nervous system including, for example, spinal cord injury(e.g., mechanical, compressive, ischemic, infective, or chemical). Inthese particular tests, outcome measures are the same as those used forperipheral neuropathic pain.

Therapy and Other Uses

The methods of this invention are useful, for example, for thediagnosis, treatment, reduction, or prevention of various forms of pain.

Pain can take a variety of forms depending on its origin. Pain may bedescribed as being peripheral neuropathic if the initiating injuryoccurs as a result of a complete or partial transection of a nerve ortrauma to a nerve plexus. Alternatively, pain is described as beingcentral neuropathic following a lesion to the central nervous system,such as a spinal cord injury or a cerebrovascular accident. Inflammatorypain is a form of pain that is caused by tissue injury or inflammation(e.g., in postoperative pain or rheumatoid arthritis). Following aperipheral nerve injury, symptoms are typically experienced in a chronicfashion, distal to the site of injury and are characterized byhyperesthesia (enhanced sensitivity to a natural stimulus), hyperalgesia(abnormal sensitivity to a noxious stimulus), allodynia (widespreadtenderness associated with hypersensitivity to normally innocuoustactile stimuli), and/or spontaneous burning or shooting lancinatingpain. In inflammatory pain, symptoms are apparent, at least initially,at the site of injury or inflamed tissues and typically accompanyarthritis-associated pain, musculo-skeletal pain, and postoperativepain. Nociceptive pain is the pain experienced in response to a noxiousstimulus, such as a needle prick or during trauma or surgery. Functionalpain refers to conditions in which there is no obvious peripheralpathology or lesion to the nervous system. This particular form of painis generated by abnormal function of the nervous system and conditionscharacterized by such pain include fibromyalgia, tension-type headache,and irritable bowel syndrome. The different types of pain may coexist orpain may be transformed from inflammatory to neuropathic during thenatural course of the disease, as in post-herpetic neuralgia.

The methods of this invention are useful for the diagnosis, treatment,reduction, or prevention of various forms of pain, namely inflammatorypain, nociceptive pain, functional pain, and neuropathic pain, whetheracute or chronic. Exemplary conditions that may be associated with paininclude, for example, soft tissue, joint, bone inflammation and/ordamage (e.g., acute trauma, osteoarthritis, or rheumatoid arthritis),myofascial pain syndromes (fibromylagia), headaches (including clusterheadache, migraine, and tension type headache), myocardial infarction,angina, ischemic cardiovascular disease, post-stroke pain, sickle cellanemia, peripheral vascular occlusive disease, cancer, inflammatoryconditions of the skin or joints, diabetic neuropathy, and acute tissuedamage from surgery or traumatic injury (e.g., burns, lacerations, orfractures). The present invention is also useful for the treatment,reduction, or prevention of musculo-skeletal pain (after trauma,infections, and exercise), neuropathic pain caused by spinal cordinjury, tumors, compression, inflammation, dental pain, episiotomy pain,deep and visceral pain (e.g., heart pain, bladder pain, or pelvic organpain), muscle pain, eye pain, orofacial pain (e.g., odontalgia,trigeminal neuralgia, glossopharyngeal neuralgia), abdominal pain,gynecological pain (e.g., dysmenorrhea and labor pain), pain associatedwith nerve and root damage due to trauma, compression, inflammation,toxic chemicals, metabolic disorders, hereditary conditions, infections,vasculitis and autoimmune diseases, central nervous system pain, such aspain due to spinal cord or brain stem damage, cerebrovascular accidents,tumors, infections, demyelinating diseases including multiple sclerosis,low back pain, sciatica, and post-operative pain. Conditions that areamenable to treatment according to the present invention are describedin detail, for example, in U.S.S.N. 10/987,289 and 11/584,449, as wellas U.S. Pat. No. 6,593,331, each of which are hereby incorporated byreference.

Combination Therapy

The compounds of the present invention (e.g., any of Compounds (1)-(39)or a compound according to Formula (I) or (II)), or a tautomer, salt,solvate, prodrug, or pharmaceutical composition thereof, may beadministered either alone or in combination with one or more additionaltherapeutic agents, such as an analgesic agent used in the treatment ofnociception, inflammatory, functional, or neuropathic pain. According tothis invention, the second therapeutic agent may or may not produce atherapeutic effect when administered on its own, but results in such aneffect (e.g., pain reduction) when administered with the composition ofthe invention.

Exemplary analgesic agents include, without limitation, nonsteroidalanti-inflammatory agents (NSAIDs) (e.g. rofexocib, celecoxib,valdecoxib, paracoxib, salicylic acid, acetominophen, diclofenac,piroxican indomethacin, ibuprofen, and naproxen), opioid analgesics(e.g., propoxyphene, meperidine, hydromorphone, hydrocodone, oxycodone,morphine, codeine, and tramodol), NMDA antagonist analgesics (e.g.,2-piperidino-1 alkanol derivatives, ketamine, dextormethorphan,eliprodil, or ifenprodil), anesthetic agents (e.g., nitrous oxide,halothane, fluothane), local anesthetics (lidocaine, etidocaine,ropivacaine, chloroprocaine, sarapin, and bupivacaine), benzodiazepines(diazepam, chlordiazepoxide, alprazolam, and lorazepam), capsaicin,tricyclic antidepressants (e.g., amitriptyline, perphanazine,protriptyline, tranylcypromine, imipramine, desimipramine, andclomipramine), skeletal muscle relaxant analgesics (flexeril,carisoprodol, robaxisal, norgesic, and dantrium), migraine therapeuticagents (e.g., elitriptan, sumatriptan, rizatriptan, zolmitriptan, andnaratriptan), anticonvulsants (e.g., phenyloin, lamotrigine, pregabalin,carbamazepine, oxcarbazepine, topiramate, valproic acid, andgabapentin), baclofen, clonidine, mexilitene, diphenyl-hydramine,hydroxysine, caffeine, prednisone, methylprednisone, decadron,paroxetine, sertraline, fluoxetine, tramodol, ziconotide, and levodopa.

Further, if desired, the mammal being treated may be administered morethan one agent that inhibits the production of BH4 (e.g., thosedescribed in U.S. Ser. No. 10/987,289, hereby incorporated byreference). Optionally, the composition of the invention may containmore than one such inhibitor. Alternatively, the mammal may further beadministered with specific inhibitors of enzymes that functiondownstream of BH4, in addition to the composition of the invention.

The following non-limiting examples are illustrative of the presentinvention.

EXAMPLES

Synthesis of Formula (I) Compounds

Synthesis of Compounds (1)-(5)

Compounds (1)-(5) were prepared according to Scheme 7. In this scheme, Rcan be, for example, any group that is defined for R² in Formula (I).

Preparation of Intermediates B1-B5

General Procedure: To a cold (0° C.) clear solution of compound A (1.0mmol) and triethylamine (4.0 mmol) in dichloromethane (25 mL) was addedslowly the corresponding acid chloride (2.0 mmol) over 5 minutes. Afteraddition, the reaction mixture was stirred at 0° C. for 5 hours. Thereaction mixture was diluted with water (20 mL) and extracted withdichloromethane (2×20 mL). The combined dichloromethane layers werewashed with brine (10 mL), dried over anhydrous Na₂SO₄, and the solventwas evaporated to afford crude Intermediate B, which was then used inthe next step (Table 2).

TABLE 2 B1

Compound A (300 mg, 1.41 mmol) was reacted with 2-isopropoxy acetylchloride (300 mg, 2.82 mmol) in the presence of triethylamine (1.32 mL,9.40 mmol) and dichloromethane (7.5 mL). Compound B1 was obtained as apale brown gum (230 mg, crude). Mass (M − H): 315.0. B2

Compound A (200 mg, 0.94 mmol) was reacted with cyclopropane carbonylchloride (0.34 mL, 3.76 mmol) in the presence of triethylamine (mmol)and dichloromethane (5.0 mL). Compound B2 was obtained as a pale browngum (200 mg, 61%). ¹H NMR (CDCl₃): δ 8.10 (s, 1H), 7.34-7.30 (m, 2H),7.06 (s, 1H), 6.94-6.91 (m, 1H), 5.67 (bs, 1H), 3.61-3.56 (q, 2H), 2.93(s, J = 6.63 Hz; 2H), 1.91- 1.84 (m, 1H), 1.30-1.16 (m, 4H), 1.05-0.95(m, 4H), 0.72-0.67 (m, 2H). Mass (M + H): 313.0. B3

Compound A (300 mg, 1.41 mmol) was reacted with 2-ethoxyacetylchloride(206 mg, 1.69 mmol) in the presence of triethylamine (0.4mL, 2.82 mmol) and dichloromethane (30.0 mL). Compound B3 was obtainedas a pale brown gum (200 mg, crude). Mass (M + H): 349.0. B4

Compound A (300 mg, 1.41 mmol) was reacted with 2-isopropoxy acetylchloride (289 mg, 2.02 mmol) in the presence of triethylamine (0.6 mL,4.35 mmol) and dichloromethane (15.0 mL) to give compound B4 as a palebrown gum (230 mg, crude). Mass (M + H): 378.0. B5

Compound A (500mg, 2.35 mmol) was reacted with morpholine-4-carbonylchloride (1.08 mL, 9.40 mmol) in the presence of triethylamine (1.32 mL,9.40 mmol) and dichloromethane (15.0 mL). Compound B5 was obtained as apale brown gum (230 mg, crude).

Preparation of Compounds (1)-(5)

General Procedure: A suspension of Intermediate B (1.0 mmol) and K₂CO₃(1 mmol) in methanol (20 mL) was stirred at 26° C. for 2 hours. Thereaction mixture was concentrated under reduced pressure. The residuewas diluted with water (30 mL) and extracted with ethyl acetate (2×20mL). The combined ethyl acetate layers were washed with water (10 mL),brine (10 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the corresponding crude product (Table 3), which was purifiedby column chromatography (100-200 mesh silica gel) using 3% MeOH inchloroform as eluent.

TABLE 3 (1)

Intermediate B1 (250 mg, 0.761 mmol) was reacted with K₂CO₃ (110 mg,0.761 mmol) in MeOH (5.0 mL) to give Compound (1) (70 mg, 38.4%) as apale brown gum. ¹H NMR (DMSO-d₆: δ 10.47 (bs, 1H), 8.5 (s, 1H), 7.82(bs, 1H), 7.11 (d, J = 8.70 Hz; 1H), 7.01 (s, 1H), 6.82 (s, 1H),6.59-6.56 (m, 1H), 3.28-3.23 (m, 2H), 2.70 (t, J = 7.46 Hz; 2H),2.35-2.31 (m, 1H), 1.00 (s, 3H), 0.98 (s, 3H). Mass (M + H): 247.0. IR(cm⁻¹): 3401, 2967, 2928, 1642, 1231, 935, 796. IIPLC purity (%): 94.5(Max plot), 87.98 (254 nm), 96.9 (215 nm). (2)

Intermediate B2 (180 mg, 0.51 mmol) was reacted with K₂CO₃ (72 mg, 0.51mmol) in MeOH (5.0 mL) to give Compound (2) (80 mg, 63%) Pale brownsolid. ¹H NMR (DMSO-d₆): δ 10.49 (bs, 1H), 8.59 (s, 1H), 8.16 (t, J =5.12 Hz; 1H), 7.11 (d, J = 8.78 Hz; 1H), 7.02 (s, 1H), 6.81 (s, 1H),6.59-6.56 (m, 1H), 3.32-3.27 (m, 2H), 2.71 (t, J = 7.31 Hz; 2H),1.55-1.49 (m, 1H), 0.69-0.61 (m, 4H). Mass (M + H): 245.0. IR (cm⁻¹):3420, 2925, 1648, 1456, 1242, 929. HPLC purity (%): 96.32 (Max plot),96.29 (254 nm), 98.8 (215 nm). (3)

Intermediate B3 (250 mg, 0.718 mmol) was reacted with K₂CO₃ (99 mg,0.718 mmol) in MeOH (5.0 mL) to give Compound (3) (100 mg, 52.9%) Palebrown solid. ¹H NMR (DMSO-d₆): δ 10.49 (bs, 1H), 8.59 (s, 1H), 7.73 (t,J = 5.61 Hz; 1H), 7.11 (d, J = 8.29 Hz; 1H), 7.04 (s, 1H), 6.84 (s, 1H),6.59-6.57 (m, 1H), 3.81 (s, 2H), 3.47- 3.42 (m, 2H), 3.37-3.32 (m, 2H),2.76 (t, J = 7.56 Hz; 2H), 1.12 (t, J = 6.83 Hz; 3H). Mass (M + H):263.0. IR (cm⁻¹): 3368, 2921, 1644, 1459, 1374, 671. HPLC purity (%):97.31 (Max plot), 91.76 (254 nm), 97.63 (215 nm). (4)

Intermediate B4 (532 mg, 1.41 mmol) was reacted with K₂CO₃ (195 mg, 1.41mmol) in MeOH (6.0 mL) to give Compound (4) (150 mg, 38.4%) as a palebrown gum. ¹H NMR (CDCl₃): δ 7.91 (bs, 1H), 7.23-7.21 (m, 1H), 7.05-7.02(m, 2H), 6.08-6.78 (m, 2H), 5.13 (s, 1H), 3.91 (s, 2H), 3.63-3.53 (m,3H), 1.09 (s, 3H), 1.08 (s, 3H). Mass (M + H): 277.0. IR (cm⁻¹): 3398,2972, 1655, 1459, 1213, 935. HPLC purity (%): 98.72 (Max plot), 98.73(254 nm), 99.23 (215 nm). (5)

Intermediate B5 (400 mg, 0.99 mmol) was reacted with K₂CO₃ (137 mg, 0.99mmol) in MeOH (8.0 mL) to give Compound (5) (170 mg, 59%) Pale brownsolid, ¹H NMR (DMSO-d₆): δ 10.45 (bs, 1H), 8.56 (s, 1H), 7.10 (d, J =8.70 Hz; 1H), 7.01 (s, 1H), 6.83 (s, 1H), 6.63- 6.56 (m, 2H), 3.53 (t, J= 4.35 Hz; 4H), 3.26-3.25 (m, 6H), 2.73 (t, J = 7.46 Hz; 2H). Mass (M +H): 290.0. IR (cm⁻¹): 3409, 2921, 2853, 1629, 1534, 1263, 1112, 851.HPLC purity (%): 97.27 (Max plot), 98.47 (254 nm), 98.88 (215 mn).Synthesis of Compounds (6), (7), and (8)

Compounds (6)-(8) were each synthesized according to the procedure ofScheme 8. In this procedure, R can be, for example, any group as definedfor R² in Formula (I).

Preparation of Intermediate D

To a cold (0° C.), clear solution of Intermediate C (2.5 g, 11.75 mmol)and triethylamine (8.25 mL, 58.77 mmol) in dichloromethane (80.0 mL) wasadded slowly acetyl chloride (2.67 mL, 37.61 mmol) over 10 minutes.After the addition was complete, the reaction mixture was allowed towarm at room temperature and stirred for 2 hours. The reaction mixturewas diluted with dichloromethane (20 mL) and washed with water (2×20 mL)and brine (30 mL), dried over anhydrous Na₂SO₄, and the solvent wasremoved to afford the crude Intermediate D (3.3 g, 88%) as a pale browngum. Mass (M+H): 261.0.

Preparation of Intermediate E

A suspension of Intermediate D (3.3 g, 12.69 mmol) and K₂CO₃ (1.75 g,12.69 mmol) in methanol (40.0 mL) was stirred at 26° C. for 2 hours. Thereaction mixture was concentrated under reduced pressure; the residuewas then diluted with water (50 mL) and extracted with ethyl acetate(2×50 mL). The combined ethyl acetate layers were washed with water (20mL) and brine (20 mL), dried over anhydrous Na₂SO₄, and the solvent wasremoved to afford the corresponding crude Intermediate E (2.3 g,83.15%), as a pale brown gum. Mass (M+H): 219.0.

Preparation of Intermediate F

To a solution of Intermediate E (2.3 g, 10.55 mmol) in a 30% NaOHsolution (1.3 mL) at 26° C., dimethyl sulfate (1.7 mL, 17.93 mmol) wasadded slowly for 15 minutes. After the addition was complete, thereaction mixture was stirred at ambient temperature for 2 hours. Thereaction mixture was acidified with 2N HCl (pH ˜2), diluted with water(20 mL), and extracted with ethyl acetate (2×50 mL). The combined ethylacetate layers were washed with water (2×20 mL) and brine (20 mL), driedover anhydrous Na₂SO₄, and the solvent was removed to afford the crudeIntermediate F, which was washed with ether (2×10 ml) and n-pentane (10mL) and then dried to afford the Intermediate F (1.5 g, 61.4%), as offwhite solid. ¹H NMR (CDCl₃): δ 8.02 (bs, 1H), 7.26 (s, 1H), 7.04-7.01(m, 2H), 6.89-6.86 (m, 1H), 5.54 (bs, 1H), 3.86 (s, 3H), 3.60 (q, 2H),2.94 (t, J=6.73 Hz; 2H), 1.93 (s, 3H). Mass (M+H): 233.0.

Preparation of Intermediate G

A solution of Intermediate F (1.4 g, 6.03 mmol) in a 10% NaOH solution(13.5 mL) was stirred at 80° C. for 8 hours. The reaction mixture wasbasified with 20% NaOH (pH ˜10) and extracted with ethyl acetate (2×50mL). The combined ethyl acetate layers were washed with water (30 mL)and brine (20 mL), dried over anhydrous Na₂SO₄, and the solvent wasremoved to afford the crude product, which was washed with pet ether(2×10 ml) and n-pentane (10 mL) then dried to afford Intermediate G (1.2g, crude), as pale brown solid. ¹H NMR (CDCl₃): δ 10.58 (bs, 1H), 7.20(t, J=8.78 Hz; 1H), 7.07 (s, 1H), 6.98 (s, 1H), 6.71-6.68 (m, 1H), 3.75(s, 3H), 2.81-2.69 (m, 4H), 1.39 (bs, 2H).

Preparation of Intermediates H1-H3

General Procedure: To a cold (0° C.) solution of Intermediate G (1.0mmol) and triethylamine (1.5 mmol) in dichloromethane (30 mL), therequisite sulfonyl chloride (1.2 mmol) was added slowly for 5 minutes.After the addition was complete, the reaction mixture was allowed toreach room temperature and stirred for 2 hours. The reaction mixture wasdiluted with dichloromethane (20 mL), washed with water (2×10 mL) andbrine (20 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude Intermediate H (Table 4), which was purified bycolumn chromatography (silica gel 100-200 mesh) using 40% ethyl acetatein petroleum ether as eluent.

TABLE 4 H1

Intermediate G (300 mg, 1.57 mmol) was reacted with methanesulfonylchloride (271 mg, 2.36 mmol) and triethylamine (0.660 mL, 4.73 mmol) indichloromethane (20 mL) to give Intermediate H1 (140 mg, crude), aswhite solid. ¹H NMR (CDCl₃): δ 7.95 (bs, 1H), 7.29 (d, J = 8.78 Hz; 1H),7.07 (s, 1H), 7.03 (s, 1H), 6.90-6.87 (m, 1H), 4.23 (m, 1H), 3.87 (s,3H), 3.47 (q, 2H), 3.03 (t, J = 6.54 Hz; 2H), 2.85 (s, 3H). Mass (M +H): 269.1. H2

Intermediate G (230 mg, 1.31 mmol) was reacted with isopropane sulfonylchloride (225 mg, 1.57 mmol) and triethylamine (0.28 mL, 1.97 mmol) indichloromethane (20 mL) to give Intermediate H2 (200 mg, crude), as apale brown gum. ¹H NMR (CDCl₃): δ 7.97 (bs, 1H), 7.27 (d, J = 8.78 Hz;1H), 7.07 (s, 1H), 7.03 (s, 1H), 6.89-6.87 (m, 1H), 4.06 (m, 1H), 3.87(s, 3H), 3.45 (q, 2H), 3.15-3.08 (m, 1H), 3.03 (t, J = 6.63 Hz; 2H),1.30 (s, 3H), 1.29 (s, 3H). Mass (M + H): 297.0. H3

Intermediate G (400 mg, 2.10 mmol) was reacted with ethylsulfonylchloride (395 mg, 2.52 mmol) and triethylamine (0.88 mL, 6.31 mmol) indichloromethane (20.0 mL) to give Intermediate H3 (400 mg, crude), as apale brown gum. ¹H NMR (CDCl₃): δ 7.97 (bs, 1H), 7.27 (d, J = 8.78 Hz;1H), 7.06 (s, 1H), 7.03 (s, 1H), 6.89-6.87 (m, 1H), 4.18 (m, 1H), 3.87(s, 3H), 3.43 (q, 2H), 3.03 (t, J = 6.42 Hz; 2H), 2.80 (d, J = 6.63 Hz;2H), 2.18-2.11 (m, 1H), 1.02 (s, 3H), 1.01 (s, 3H). Mass (M + H): 311.0.

Preparation of Compounds (6)-(8)

General Procedure: To a cold (−40° C.) solution of Intermediate H (1.0mmol) in dichloromethane (20 mL) was added slowly BBr₃ (4.0 mmol). Afterthe addition was complete, the reaction mixture was allowed to reach 0°C. and then stirred for 2 hours. The reaction mixture was diluted withdichloromethane (20 mL) and washed with water (2×10 mL). The combineddichloromethane layers were washed with water (10 mL) and brine (10 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude product, which was purified by column chromatography (silica gel100-200 mesh) using 40% ethyl acetate in petroleum ether as eluent(Table 5).

TABLE 5 (6)

Intermediate H1 (130 mg, 0.48 mmol) was reacted with BBr₃ (0.19 mL, 1.95mmol) in dichloromethane (20.0 mL) to give Compound (6) (20 mg, 16%), aswhite solid. ¹H NMR (DMSO- d₆): δ 10.53 (bs, 1H), 8.62 (s, 1H),7.13-7.07 (m, 3H), 6.80 (s, 1H), 6.59-6.57 (m, 1H), 3.19-3.13 (m, 2H),2.83-2.76 (m, 5H). Mass (M − H): 253.0. IR (cm⁻¹): 3443, 2923, 1635,1318, 1160, 762. HPLC purity (%): 97.12 (Max plot), 97.84 (254 nm),97.91 (215 nm). (7)

Intermediate H2 (200 mg, 0.67 mmol) was reacted with BBr₃ (0.26 mL, 2.71mmol) in dichloromethane (20 mL) to give Compound (7) (45 mg, 23.5%), aswhite solid, ¹H NMR (DMSO- d₆): δ 10.51 (bs, 1H), 8.60 (s, 1H),7.12-7.06 (m, 3H), 6.79 (s, 1H), 6.59-6.56 (m, 1H), 3.19-3.10 (m, 3H),2.79-2.75 (m, 2H), 1.20 (s, 3H), 1.18 (s, 3H). Mass (M + H): 283.0. IR(cm⁻¹): 3408, 2925, 1460, 1305, 1134, 792. HPLC purity (%): 95.48 (Maxplot), 95.68 (215 nm). (8)

Intermediate H3 (400 mg, 1.29 mmol) was reacted with BBr₃ (0.5 mL, 5.16mmol) in dichloromethane (30 mL) to give Compound (8) (85 mg, 22.3%) asbrown solid. ¹H NMR (DMSO-d₆): δ 10.52 (bs, 1H), 8.60 (s, 1H), 7.13-7.07(m, 3H), 6.79 (s, 1H), 6.59-6.57 (m, 1H), 3.18-3.13 (m, 2H), 2.79-2.75(m, 4H), 2.05-2.01 (m, 1H), 0.98 (s, 3H), 0.96 (s, 3H). Mass (M + H):297.0. IR (cm⁻¹): 3424, 2924, 1305, 1138, 793. HPLC purity (%): 98.64(Max plot), 96.97 (254 nm). 98.37 (215 nm).

Synthesis of Compound (9)

Compound (9) was prepared according to the procedure of Scheme 9.

To a cold (0° C.) solution of Intermediate C (500 mg, 2.35 mmol) andtriethylamine (3.5 mL, 25.51 mmol) in dichloromethane (20.0 mL), wasadded slowly ethyl sulfonyl chloride (453 mg, 3.52 mmol) over 5 minutes.After the addition was complete, the reaction mixture was allowed toreach room temperature and stirred for 2 hours. The reaction mixture wasdiluted with dichloromethane (50 mL), washed with water (2×10 mL) andbrine (20 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude product, which was purified by column chromatography(silica gel 100-200 mesh) using 30% ethyl acetate in petroleum ether aseluent. Compound (9) was obtained in 15 mg as a pale brown gum. ¹H NMR(DMSO-d₆): δ 10.52 (bs, 1H), 8.61 (s, 1H), 7.16-7.07 (m, 3H), 6.79 (s,1H), 6.59-6.57 (m, 1H), 3.17-3.12 (m, 3H), 2.97-2.91 (m, 2H), 2.79-2.75(m, 2H), 1.15 (t, J=7.22 Hz; 3H). Mass (M+H): 268.9. IR (cm⁻¹): 3398,2925, 1307, 1134, 790. HPLC purity (%): 93.74 (Max plot), 92.54 (215nm).

Synthesis of Compounds (10)-(12)

Compounds (10)-(12) were prepared according to the procedure shown inScheme 10.

Preparation of Intermediate K

To a cold (0° C.) solution of formaldehyde (37% aqueous solution; 4.0mL, 49.32 mmol) and acetic acid (46.0 g, 762.28 mmol) in dioxane (40.0mL), was added dimethylamine (40% aqueous solution; 6.4 mL, 58.29 mmol)dropwise for 15 minutes. The reaction was then stirred for an additional15 minutes. At the same temperature, a solution of Intermediate J (10.0g, 44.84 mmol) in dioxane (70.0 mL) was added slowly. After the additionwas complete, the reaction mixture was stirred at 0° C. for 2 hours. Thereaction mixture was diluted with dioxane (100 mL) and then basified(pH˜10) using an aqueous 10% KOH solution. The obtained solid wascollected by filtration, washed with water (3×50 mL) and dried to affordcrude Intermediate K (12.0 g, 95%) as an off white solid, which was usedin the next step without further purifications. ¹H NMR (DMSO-d₆): δ10.72 (bs, 1H), 7.47 (d, J=7.42 Hz; 2H), 7.40-7.29 (m, 3H), 7.23 (d,J=8.78 Hz; 1H), 7.15 (m, 2H), 6.80-6.77 (m, 1H), 5.07 (s, 2H), 3.47 (s,2H), 2.49 (s, 6H). Mass (M+H): 281.1.

Preparation of Intermediate L

To a solution of Intermediate K (14 g, 50.0 mmol) in water (40.0 mL) andethanol (157.0 mL) at room temperature, sodium cyanide (20.0 g, 408.0mmol) was added, and the reaction mixture was stirred at 100° C. for 60hours. The reaction mixture was concentrated; the aqueous residue wasthen diluted with water (100 mL) and extracted with ethyl acetate (2×50mL) to remove the impurities. The aqueous layer was acidified (pH˜2)using diluted HCl and extracted with dichloromethane (3×50 mL). Thecombined organic layers were washed with water (30 mL) and brine (25mL), dried over anhydrous Na₂SO₄, and the solvent was removed to affordthe crude Intermediate L (4.5 g, 32%) as pale brown solid. ¹H NMR(CDCl₃): δ 7.98 (bs, 1H), 7.48-7.46 (m, 2H), 7.39-7.28 (m, 4H),7.18-7.13 (m, 2H), 6.96-6.94 (m, 1H), 5.10 (s, 2H), 3.78 (s, 2H). Mass(M+H): 282.1.

Preparation of Intermediates M1-M3

General Procedure: To a cold (0° C.) solution of Intermediate L (1.0mmol), EDC.HCl (1.3 mmol), HOBt (1.3 mmol), and triethylamine (1.0 mmol)in dichloromethane (30 mL) was added slowly a solution of correspondingamine (1.1 mmol) in dichloromethane (2 mL) over 5 minutes. After theaddition was complete, the reaction mixture was allowed to reach roomtemperature and stirred for 16 hours. The reaction mixture was dilutedwith dichloromethane (25 mL) and washed sequentially with water (10 mL),10% NaHCO₃ solution (10 mL), water (10 mL), and brine solution (20 mL).The organic layer was then dried over anhydrous Na₂SO₄, and the solventwas removed to afford the crude Intermediate M (Table 6), which waspurified by column chromatography (silica gel 100-200 mesh) using 1%MeOH in chloroform as eluent.

TABLE 6 M1

Intermediate L (125 mg, 0.445 mmol) was reacted with methoxy ethylamine(37 mg, 0.49 mmol), EDC•HCl (111 mg, 0.577 mmol), HOBt (78 mg, 0.577mmol), and Et₃N (0.063 mL, 0.45 mmol) to give Intermediate M1 (110 mg,73%), off white solid. ¹H NMR (CDCl₃): δ 8.09 (bs, 1H), 7.48-7.46 (m,2H), 7.39-7.28 (m, 4H), 7.12-7.07 (m, 2H), 6.98-6.96 (m, 1H), 6.04 (b,1H), 5.09 (s, 2H), 3.70 (s, 2H), 3.37-3.32 (m, 4H), 3.18 (s, 3H). Mass(M + H): 339.2. M2

Intermediate L ((500 mg, 1.779 mmol) was reacted with 2-aminopyridine(185 mg, 1.96 mmol), EDC•HCl (442 mg, 2.31 mmol), HOBt (312 mg, 2.31mmol), and Et₃N (0.25 mL, 1.78 mmol) to give Intermediate M2 (180 mg,29%), off white solid. ¹H NMR (CDCl₃): δ 8.26 (d, J = 8.59 Hz; 1H), 8.15(m, 2H), 8.00 (bs, 1H), 7.70-7.66 (m, 1H), 7.45-7.43 (m, 2H), 7.36-7.25(m, 4H), 7.22- 7.20 (s, 1H), 7.11 (s, 1H), 7.00-6.96 (m, 2H), 5.07 (s,2H), 3.88 (s, 2H). Mass (M + H): 358.2. M3

Intermediate L ((500 mg, 1.779 mmol) was reacted with 3-aminopyridine(185 mg, 1.96 mmol), EDC•HCl (442 mg, 2.31 mmol), HOBt (312 mg, 2.31mmol), and Et₃N (0.25 mL, 1.78 mmol) to give Intermediate M3 (180 mg,35%), off white solid. ¹H NMR (CDCl₃): δ 8.31-8.25 (m, 1H), 8.12-8.03(m, 2H), 7.45-7.43 (m, 2H), 7.36-7.32 (m, 2H), 7.28-7.20 (m, 4H), 7.09(m, 1H), 7.03-7.00 (m, 1H), 5.08 (s, 2H), 3.88 (s, 2H). Mass (M + H):358.1.Preparation of Intermediates N2 and N3

General Procedure: To a cooled solution of Intermediate M (1.0 mmol) inTHF (30 mL) at 0° C., a solution of BH₃DMS (15.0 mmol) was added at 0°C. After the addition was complete, the reaction mixture was stirred at70° C. for 2 hours. The reaction mixture was cooled to 0° C., quenchedwith a mixture of methanol (2.0 mL) and 2N HCl (5.0 mL). After refluxingfor 1 hour, the solvent was evaporated and the aqueous residue wasbasified (pH˜10) using 2N NaOH solution. The aqueous layer was extractedwith ethyl acetate (2×50 mL), washed with water (2×15 mL) and brine (15mL), dried over dried over anhydrous Na₂SO₄, and evaporated to yield thecrude product, which was purified by column chromatography (silica gel100-200 mesh) using 80% ethyl acetate in pet ether as eluent to affordIntermediate N (Table 7).

TABLE 7 N2

Intermediate M2 (150 mg, 0.42 mmol) was reacted with BH₃•DMS (0.6 mL,6.30 mmol) in THF (20.0 mL) to give Intermediate N2 (75 mg, 52%), offwhite solid. ¹H NMR (CDCl₃): δ 8.25 (bs, 1H), 8.09-8.08 (m, 1H),7.47-7.23 (m, 7H), 7.14 (s, 1H), 6.98-6.92 (m, 2H), 6.57-6.54 (m, 1H),6.35 (d, J = 8.29 Hz; 1H), 5.07 (s, 2H), 4.61 (bs, 1H), 3.60-3.56 (q,2H), 3.03 (t, J = 6.83 Hz, 2H). Mass (M + H): 344.2. N3

Intermediate M3 (300 mg, 0.84 mmol) was reacted with BH₃•DMS (1.15 mL,12.63 mmol) in THF (20.0 mL) to give Intermediate N3 (120 mg, 42%), offwhite solid. ¹H NMR (CDCl₃): δ 8.04-7.94 (m, 3H), 7.47-7.25 (m, 6H),7.09-7.03 (m, 3H), 6.96 (d, J = 8.78 Hz; 1H), 6.87-6.84 (m, 1H), 5.08(s, 2H), 3.78 (bs, 1H), 3.44 (bs, 2H), 3.05 (t, J = 6.54 Hz, 2H). Mass(M + H): 344.2.

Preparation of Compounds (II) and (12)

General Procedure: To a cold (−70° C.) solution of Intermediate O (1.0mmol) in dichloromethane (30 mL), BCl₃ (0.1 M in DCM)(1.4 mmol) wasadded slowly. After the addition was complete, the reaction mixture wasallowed to reach room temperature and stirred for 1 hour. The reactionmixture was diluted with dichloromethane (20 mL), washed with water(2×20 mL) and brine (10 mL), dried over anhydrous Na₂SO₄, and thesolvent was removed to afford the crude product (Table 8), which waspurified by PREP-TLC using 6% MeOH in chloroform as eluent.

TABLE 8 (11)

Intermediate N2 (75 mg, 0.218 mmol) was reacted with BCl₃ (3.05 mL,0.305 mmol) in dichloromethane (10 mL) to give Compound (11) (18 mg,30%) as an off white solid. ¹H NMR (DMSO-d₆): δ 10.48 (bs, 1H), 8.58 (s,1H), 7.98 (m, 1H), 7.34 (m, 1H), 7.12 (d, J = 8.70 Hz; 1H), 7.06 (s,1H), 6.86 (s, 1H), 6.60-6.43 (m, 4H), 3.49-3.44 (m, 2H), 2.85-2.81 (m,2H). Mass (M + H): 254.1. IR (cm⁻¹): 3406, 2920, 2854, 1606, 1210, 1095,771. HPLC purity (%): 96.37 (Max plot), 96.26 (254 nm), 96.18 (215 nm).(12)

Intermediate N3 (120 mg, 0.348 mmol) was reacted with BCl₃ (5.0 mL, 0.5mmol) in dichloromethane (15.0 mL) to give Compound (12) (25 mg, 28%) asan off while solid. ¹H NMR (DMSO- d₆): δ 10.52 (bs, 1H), 8.60 (s, 1H),7.98 (s, 1H), 7.75 (m, 1H), 7.13-7.05 (m, 3H), 6.91 (d, J = 8.29 Hz;1H),6.82 (s, 1H), 6.60-6.57 (m, 1H), 5.91 (s, 1H), 3.30-3.25 (m, 2H),2.87-2.83 (m, 2H). Mass (M + H): 254.1. IR (cm⁻¹): 3398, 2919, 2851,1586, 1467, 791. IIPLC purity (%): 95.72 (Max plot), 94.43 (254 nm),96.01 (215 nm).Preparation of Compound (10)

A suspension of Intermediate M1 (100 mg, 0.29 mmol) and 10% Pd/C (30 mg,dry) in MeOH (10.0 mL) was hydrogenated (50 psi H₂ pressure) at roomtemperature for 5 hours. The reaction mixture was filtered, and the cakewas washed with methanol (3×5 mL). The combined filtrates wereconcentrated under reduced pressure to give crude Compound (10), whichwas purified by PREP-TLC using 5% MeOH in chloroform as eluent to affordthe product (30 mg, 41%) as an off white solid. NMR (DMSO-d₆): δ 10.54(bs, 1H), 8.57 (s, 1H), 7.85 (s, 1H), 7.11 (d, J=8.78 Hz; 1H), 7.06 (s,1H), 6.83 (s, 1H), 6.58 (dd, 1H), 3.40 (s, 2H), 3.34-3.30 (m, 2H),3.22-3.17 (m, 5H). Mass (M+H): 249.1. IR (cm⁻¹): 3378, 3323, 2934, 1641,1228, 1019, 669. HPLC purity (%): 99.73 (Max plot), 99.71 (215 nm).

Preparation of Compounds (13)-(15)

Compounds (13)-(15) can be synthesized according to the procedure shownin Scheme 10 by using one of the following amines in the preparation ofIntermediate M (Table 9).

TABLE 9 Compound Amine reagent (13)

(14)

(15)

Synthesis of Compound (16)

Compound (16) was prepared according to the procedure in Scheme 11.

To a cold (0° C.) solution of Intermediate 0 (250 mg, 1.16 mmol) andtriethylamine (0.32 mL, 2.32 mmol) in dichloromethane (5.0 mL) was addedslowly methoxyacetyl chloride (0.12 mL, 1.39 mmol) over 5 minutes. Afterthe addition was complete, the reaction mixture was allowed to reachroom temperature and stirred for 2 hours. The reaction mixture wasdiluted with dichloromethane (20 mL), washed with water (2×20 mL) andbrine (20 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude product. The material was then washed with petroleumether (2×4 mL), n-pentane (3 mL), and dried to afford Compound (16) (20mg, 68.2%) as pale yellow solid. ¹H NMR (CDCl₃): δ 8.15 (bs, 1H),7.29-7.22 (m, 2H), 7.09 (s, 1H), 6.97-6.93 (m, 1H), 6.68 (bs, 1H), 3.87(s, 2H), 3.64-3.59 (m, 2H), 3.33 (s, 3H), 2.95 (t, J=6.84, Hz; 2H). Mass(M+H): 251.0. HPLC purity (%): 98.87 (Max plot), 98.00 (254 nm), 98.88(215 nm).

Synthesis of Compound (17)

Compound (17) was prepared according the procedure described in Scheme12.

A solution of Intermediate P (1.0 g, 5.53 mmol) in concentrated HCl (0.2mL) and water (11.6 mL) was stirred at room temperature for 1 hour. Asolution of Intermediate Q (1.1 g, 4.97 mmol) in water (2.4 mL) and MeOH(12.8 mL) was added to the above mixture, which was then stirred at roomtemperature for 1 hour. The reaction mixture was cooled to 0° C. and thesolid was filtered off, washed with 9:1 aqueous methanol (5.0 mL) andwater (10.0 mL), and dried. To the solution of this compound in water(7.2 mL) and MeOH (29.0 mL) was then added Na₂HPO₄ (0.5 g, 3.54 mmol)and concentrated HCl (0.1 mL). The reaction mixture was then stirred atreflux for 20 hours. The reaction mixture was concentrated; the aqueousresidue was then diluted with water (20 mL), saturated with Na₂CO₃, andextracted with dichloromethane (3×25 mL). The combined dichloromethanelayers were dried over anhydrous Na₂SO₄, and the solvent was removed toafford the crude Intermediate S, which was purified by columnchromatography (silica gel 100-200 mesh) using 2% (MeOH/NH₃) inchloroform as eluent to afford the product (80 mg, 6%) as brown solid.¹H NMR (DMSO-d₆): δ 11.41 (bs, 1H), 8.12 (s, 1H), 7.59-7.53 (m, 2H),7.38 (s, 1H), 3.15 (s, 3H), 2.83 (s, 4H). Mass (M+H): 239.0.

Preparation of Compound (17)

To a cold (0° C.) solution of Intermediate S (150 mg, 0.63 mmol) andtriethylamine (0.13 mL, 0.94 mmol) in dichloromethane (10.0 mL) wasadded slowly a solution of methoxyacetyl chloride (0.06 mL, 0.69 mmol)in dichloromethane (2.0 mL) over 5 minutes. After the addition wascomplete, the reaction mixture was allowed to reach room temperature andstirred for 2 hours. The reaction mixture was diluted withdichloromethane (20 mL), washed with water (2×20 mL) and brine (10 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude product. This material was then purified by column chromatography(silica gel 100-200 mesh) using 2% MeOH in chloroform as eluent toafford Compound (17) (80 mg, 41%) as off white solid. ¹H NMR (CDCl₃): δ8.40 (bs, 1H), 8.25 (s, 1H), 7.75 (d, J=8.39 Hz; 1H), 7.50 (d, J=8.78Hz; 1H), 7.24 (s, 1H), 6.66 (bs, 1H), 3.89 (s, 2H), 3.68-3.63 (m, 2H),3.36 (s, 3H), 3.09 (s, 3H), 3.06-3.03 (t, J=7.03 Hz; 2H). Mass (M−H):309.0. IR (cm⁻¹): 3344, 2925, 1656, 1289, 1147, 750. HPLC purity (%):98.90 (Max plot), 94.95 (254 nm), 97.96 (215 nm).

Synthesis of Compound (18)

Compound (18) was synthesized according to the procedure shown in Scheme13.

Preparation of Intermediate T

To a solution of Intermediate T (2.5 g, 15.41 mmol) in ether (50.0 mL)was added a solution of oxalyl chloride (5.4 mL, 61.67 mmol) in ether(15.0 mL) at room temperature. The resulting reaction was stirred at 40°C. for 16 hours. The reaction mixture was filtered, and the resultingsolid was washed with ether (2×20 mL). The solid was then added to asaturated solution of NH₃ in dioxane (100.0 mL) and stirred for 4 hours.The reaction mixture was basified with Na₂CO₃, and concentrated to yieldthe crude product, which was purified by column chromatography (silicagel 100-200 mesh) using 70% ethyl acetate in petroleum ether as eluentto afford Intermediate U (1.2 g, 31%) pale yellow solid. ¹H NMR(DMSO-d₆): δ 12.75 (bs, 1H), 9.08 (s, 1H), 8.93 (s, 1H), 8.19-8.15 (m,2H), 7.86 (s, 1H), 7.74 (d, J=8.78 Hz; 1H). Mass (M−H): 232.0.

Preparation of Intermediate V

To a suspension of lithium aluminum hydride (3.26 g, 85.0 mmol) in THF(150.0 mL) at room temperature was added a solution of Intermediate U(1.0 g, 4.29 mmol) was added. The resulting mixture was stirred at 70°C. for 48 hours. The reaction mixture was then cooled to 0° C., quenchedwith ice cold water (5.0 mL), and filtered. The cake was washed withethyl acetate (3×100 mL), and the combined filtrates were extracted. Theseparated organic layer was washed with water (25 mL) and brine (15 mL),dried over dried over anhydrous Na₂SO₄, and evaporated to yield crudeIntermediate V, which was purified by column chromatography (silica gel100-200 mesh) using (5:94:1 to 20:79:1) MeOH: chloroform: aq NH₃ as theeluent to afford the product (400 mg, 53.2%) as a brown gum. ¹H NMR(DMSO-d₆): δ 10.30 (s, 1H), 7.22-7.00 (m, 2H), 6.93 (s, 1H), 6.47-6.44(dd, 1H), 4.39 (bs, 2H), 2.81 (t, J=7.07 Hz; 2H), 2.66 (t, J=7.31 Hz;2H). Mass (M+H): 176.1.

Preparation of Intermediate W

To a cold (0° C.) solution of Intermediate V (500 mg, 2.86 mmol) inacetic acid (15.0 mL) was added slowly a solution of NaNO₂ (217 mg, 3.14mmol) in cold water (1.6 mL) over 5 minutes. After stirring for 5minutes, a solution of NaN₃ (204 mg, 3.14 mmol) in cold water (1.6 mL)was added slowly. After the addition was complete, the reaction mixturewas stirred at 0° C. for 2 hours. The reaction mixture was concentratedunder reduced pressure, and the crude product was purified by columnchromatography (silica gel 100-200 mesh) using (5:94:1 to 20:79:1)MeOH:chloroform:(aqueous NH₃) as the eluent to afford Intermediate W(220 mg, 38%) as a brown solid. ¹H NMR (DMSO-d₆): δ 10.97 (bs, 1H),7.42-7.32 (m, 1H), 7.21 (m, 2H), 6.82-6.80 (m, 1H), 2.79-2.74 (m, 4H).Mass (M+H): 202.1. IR (cm⁻¹): 3433, 2918, 2106, 920, 792.

Preparation of Intermediate X

To a cold (0° C.) solution of Intermediate W (200 mg, 0.995 mmol) andtriethylamine (20.14 mL, 0.995 mmol) in dichloromethane (20 mL) wasadded slowly a solution of methoxyacetyl chloride (100 mg, 0.895 mmol)in dichloromethane (5.0 mL) over 30 minutes. After the addition wascomplete, the reaction mixture was allowed to reach room temperature andstirred for 1 hour. The reaction mixture was diluted withdichloromethane (30 mL), washed with water (2×15 mL) and brine (20 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude product, which was purified by column chromatography (silica gel100-200 mesh) using 20% MeOH in chloroform as the eluent to affordIntermediate X (200 mg, 74%) as an off white solid. ¹H NMR (CDCl₃): δ8.08 (bs, 1H), 7.34 (d, J=8.59 Hz; 1H), 7.24 (s, 1H), 7.09 (s, 1H), 6.90(dd, 1H), 6.64 (b, 1H), 3.88 (s, 2H), 3.65-3.60 (q, 2H), 3.35 (s, 3H),2.96 (t, J=6.93 Hz; 2H). Mass (M+H): 274.1.

Preparation of Intermediate Y

A suspension of Intermediate X (200 mg, 0.73 mmol) and 10% Pd/C (30 mg,dry) in MeOH (20.0 mL) was hydrogenated (30 psi H₂ pressure) at roomtemperature for 1 hour. The reaction mixture was filtered throughCelite, and the cake was washed with methanol (3×5 mL). The combinedfiltrates were concentrated under reduced pressure to give crudeIntermediate Y (180 mg, crude) brown gum. ¹H NMR (DMSO-d₆): δ 10.31 (bs,1H), 7.80 (t, J=5.39 Hz; 1H), 7.01 (d, J=8.29 Hz; 1H), 6.95 (s, 1H),6.66 (s, 1H), 6.46 (dd, 1H), 4.42 (m, 2H), 3.78 (s, 2H), 3.41-3.28 (m,5H), 2.72 (t, J=7.46 Hz; 2H). Mass (M+H): 248.1.

Preparation of Compound (18)

To a cold (0° C.) solution of Intermediate Y (90 mg, 0.364 mmol) andtriethylamine (0.06 mL, 0.40 mmol) in dichloromethane (10.0 mL) wasadded slowly a solution of methanesulfonyl chloride (0.03 mL, 0.327mmol) in dichloromethane (2.0 mL) over 15 minutes. After the additionwas complete, the reaction mixture was allowed to reach room temperatureand stirred for 6 hours. The reaction mixture was diluted withdichloromethane (30 mL), washed with water (2×10 mL) and brine (10 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude product, which was purified by PREP-TLC using 5% MeOH inchloroform as the eluent to afford Compound (18) (35 mg, 30%) as a palebrown gum. ¹H NMR (CDCl₃): δ 8.12 (bs, 1H), 7.52 (s, 1H), 7.35 (d,J=8.35 Hz; 1H), 7.14-7.11 (m, 2H), 6.66 (bs, 1H), 6.33 (bs, 1H), 3.88(s, 2H), 3.63-3.60 (q, 2H), 3.36 (s, 3H), 3.00-2.96 (m, 5H). Mass (M+H):326.1. IR (cm⁻¹): 3387, 3275, 2930, 1658, 1321, 1148, 975. HPLC purity(%): 97.97 (Max plot), 97.20 (215 nm).

Synthesis of Compounds (19) and (20)

Compounds (19) and (20) were synthesized according to Scheme 14.

Preparation of Intermediate AA

POCl₃ (3.6 mL, 38.68 mmol) was added to DMF (16.5 mL) dropwise at 0°C.-10° C. The resulting mixture was stirred for 30 minutes, cooled to 0°C., and a solution of Intermediate Z (5.0 g, 35.17 mmol) in DMF (10.0mL) was added over 15 minutes. After the addition was complete, thereaction mixture was stirred at ambient temperature for 2 hours. Thereaction mixture was quenched with ice (25 g), poured into water (50mL), and NaOH (1.5 g) was added. The mixture was filtered, and theyellow colored filtrate was diluted with water (100 mL) and left tostand at room temperature for 20 hours. The solid was then filtered anddried to afford Intermediate AA (1.5 g, 62%) as a yellow solid. ¹H NMR(DMSO-d₆): δ 12.59 (bs, 1H), 10.00 (s, 1H), 8.52 (s, 1H), 8.51 (s, 1H),7.71 (s, J=8.29 Hz; 1H), 7.65 (d, J=8.70 Hz; 1H). Mass (M−H): 169.1.

Preparation of Intermediate AB

A suspension of Intermediate AA (4.2 g, 24.7 mmol) and ammonium acetate(4.18 g, 54.34 mmol) in nitromethane (263.0 mL) was stirred at 90° C.for 2 hours. The reaction mixture was concentrated under reducedpressure. The crude product was washed with 25% ethyl acetate inpetroleum ether (2×20 mL) and dried to afford Intermediate AB (3.5 g,68%) as yellow solid. ¹H NMR (DMSO-d₆): δ 10.84 (bs, 1H), 8.67 (s, 1H),8.43-8.40 (m, 2H), 8.23 (d, J=13.66 Hz; 1H), 7.68 (d, J=8.29 Hz; 1H),7.61 (d, J=8.78 Hz; 1H). Mass (M−H): 212.0.

Preparation of Intermediate AC

To a cold (0° C.) solution of Intermediate AB (3.5 g, 16.4 mmol) inmethanol and DMF (1:1; 35 mL) was added portionwise NaBH₄ (7.08 g, 18.73mmol) over 15 minutes. After the addition was complete, the reactionmixture was allowed to reach 10° C. and stirred for 2 hours.

The reaction mixture was quenched with water (10 mL) and concentratedunder reduced pressure. The resulting aqueous residue was diluted withwater (25 mL) and extracted with ethyl acetate (2×50 mL). The combinedethyl acetate layers were washed with water (30 mL) and brine solution(25 mL), dried over anhydrous Na₂SO₄, and the solvent was removed toafford the crude Intermediate AC, which was purified by columnchromatography (silica gel 100-200 mesh) using 20% ethyl acetate inpetroleum ether as the eluent to afford the product (2.5 g, 71.4%) aspale yellow solid. ¹H NMR (CDCl₃): δ 8.39 (bs, 1H), 7.93 (s, 1H),7.48-7.43 (m, 2H), 7.21 (s, 1H), 4.68 (t, J=6.84 Hz, 2H), 3.49 (t,J=6.84 Hz, 2H). Mass (M−H): 214.0.

Preparation of Intermediate AD

A suspension of Intermediate AC (2.5 g, 11.6 mmol), zinc powder (17.9 g)in methanol (330.0 mL) and 2N HCl (330.0 mL) was stirred at 85° C. for 2hours. The reaction mixture was basified (pH˜10) and filtered. The cakewas washed with methanol (3×10 mL), and the combined filtrate wasconcentrated under reduced pressure. The residue was dissolved in 5%MeOH in chloroform and washed with water. The organic layer was driedover anhydrous Na₂SO₄, and the solvent was removed to afford the crudeIntermediate AD (1.5 g, 70%) as a brown gum. ¹H NMR (DMSO-d₆): δ 11.43(bs, 1H), 8.09 (s, 1H), 7.49 (d, J=8.49 Hz; 1H), 7.44-7.35 (m, 2H),2.84-2.77 (m, 4H), 3.29 (t, J=7.03 Hz, 2H). Mass (M+H): 186.0.

Preparation of Compound (19)

To a cold (0° C.) solution of Intermediate AD (300 mg, 1.62 mmol) andtriethylamine (1.3 mL, 3.24 mmol) in dichloromethane (10.0 mL), wasadded slowly methoxyacetyl chloride (0.22 mL, 2.43 mmol) over 5 minutes.After the addition was complete, the reaction mixture was allowed toreach room temperature and stirred for 3 hours. The reaction mixture wasdiluted with dichloromethane (30 mL), washed with water (2×15 mL) andbrine (20 mL), dried over anhydrous Na₂SO₄, and removal of the solventyielded the crude product. This material was purified by columnchromatography (silica gel 100-200 mesh) using 2% MeOH in chloroform asthe eluent to afford Compound (19) (60 mg, 15%) as a pale brown gum. ¹HNMR (DMSO-d₆): δ 11.42 (bs, 1H), 8.11 (s, 1H), 7.89 (t, J=5.59 Hz; 1H),7.49 (d, J=8.29 Hz; 1H), 7.42-7.37 (m, 2H), 3.76 (s, 2H), 3.40-3.34 (m,2H), 3.32 (s, 3H), 2.87 (t, J=7.25 Hz; 2H). Mass (M+H): 258M. IR (cm⁻¹):3386, 3210, 2921, 2222, 1651, 1542, 1124, 639. HPLC purity (%): 94.72(Max plot), 92.32 (254 nm), 94.91 (215 nm).

Preparation of Compound (20)

To a cold (0° C.) solution of Compound (19) (50 mg, 0.194 mmol) and 3NNaOH (2.5 mL) in ethanol (3.5 mL) was added H₂O₂ (30% in water; 0.2 mL).After the addition was complete, the reaction mixture was allowed toreach room temperature and stirred for 20 hours.

The reaction mixture was concentrated, and the obtained aqueous residuewas diluted with dichloromethane (50 mL), washed with water (2×10 mL)and brine (10 mL), dried over anhydrous Na₂SO₄, and the solvent wasremoved to afford the crude product. This material was purified bycolumn chromatography (silica gel 100-200 mesh) using 8% MeOH inchloroform as the eluent to afford Compound (20) (36 mg, 33.6%) as apale brown gum. ¹H NMR (DMSO-d₆): 11.03 (bs, 1H), 8.17 (s, 1H),7.83-7.78 (m, 2H), 7.63 (d, J=8.2 Hz; 1H), 7.32 (d, J=8.39 Hz; 1H), 7.22(s, 1H), 7.06 (bs, 1H), 3.78 (s, 2H), 3.42-3.41 (m, 2H), 3.32 (s, 3H),2.88 (t, J=6.93 Hz; 2H). Mass (M+H): 275.9. IR (cm⁻¹): 3433, 32923,1645, 1239, 789. HPLC purity (%): 89.89 (Max plot), 95.47 (254 nm),90.40 (215 nm).

Synthesis of Compound (21)

Compound (21) was synthesized according to the procedure shown in Scheme15.

Preparation of Intermediate AE

To a cold (0° C.) suspension of 60% NaH (0.51 g, 15.71 mmol) in DMF(10.0 mL), a solution of Intermediate K (3.0 g, 13.43 mmol) in DMF (10.0mL) was added slowly over 5 minutes. The reaction stirred for 30minutes; iodomethane (0.98 mL, 15.71 mmol) was then added, and thereaction stirred at room temperature for 1.5 hours. The reaction mixturewas quenched with ice cold water (50 mL) and extracted with ethylacetate (2×50 mL). The combined ethyl acetate layers were washed withwater (2×20 mL) and brine (20 mL), dried over anhydrous Na₂SO₄, and thesolvent was removed to afford the crude Intermediate AE (520 mg, 96%),which was used in the next step without further purifications. ¹H NMR(CDCl₃): δ 7.48-7.46 (m, 2H), 7.39-7.35 (m, 2H), 7.32-7.28 (m, 1H),7.24-7.16 (m, 2H), 7.01-6.95 (m, 2H), 6.38 (d, J=2.92 Hz; 1H), 5.10 (s,2H), 3.75 (s, 3H). Mass (M+H): 238.1.

Preparation of Intermediate AF

POCl₃ (0.21 mL, 2.32 mmol) was added to DMF (1.0 mL) dropwise at 0°C.-10° C. The resulting mixture was stirred for 30 minutes, cooled to 0°C., and a solution of Intermediate AE (0.5 g, 2.11 mmol) in DMF (1.0 mL)was added over 15 minutes. After the addition was complete, the reactionmixture was stirred at ambient temperature for 2 hours. The reactionmixture was quenched with ice (25 g), poured into water (20 mL), andbasified (pH˜10) using 1N NaOH solution. The mixture was extracted withethyl acetate (2×50 mL), and the combined ethyl acetate layers werewashed with water (2×20 mL) and brine (20 mL), dried over anhydrousNa₂SO₄, and removal of the solvent afforded crude Intermediate AF, whichwas washed with petroleum ether (2×5 mL) and dried to afford the product(480 mg, 85%) as yellow solid. ¹H NMR (CDCl₃): δ 9.95 (s, 1H), 7.91 (s,1H), 7.62 (s, 1H), 7.50-7.48 (m, 2H), 7.48-7.30 (m, 3H), 7.26-7.24 (m,2H), 7.08-7.05 (dd, 1H), 5.15 (s, 2H), 3.84 (s, 3H). Mass (M+H): 266.0.

Preparation of Intermediate AG

A suspension of Intermediate AF (0.47 g, 1.77 mmol) and ammonium acetate(0.47 g, 6.09 mmol) in nitromethane (33.3 mL) was stirred at 90° C. for1 hour. The reaction mixture was concentrated under reduced pressure,and the obtained crude product was washed with 25% ethyl acetate inpetroleum ether (2×20 mL) and dried to afford Intermediate AG (0.48 g,87%) as yellow solid. ¹H NMR (DMSO-d₆): δ 8.23 (d, J=13.28 Hz; 1H), 7.65(d, J=13.28 Hz; 1H), 7.51-7.24 (m, 8H), 7.09-7.07 (m, 1H), 5.16 (s, 2H),3.83 (s, 3H). Mass (M+H): 309.0.

Preparation of Intermediate AH

To a cold (0° C.) solution of Intermediate AG (0.7 g, 2.27 mmol) inmethanol and DMF (2:1; 15 mL), NaBH₄ (0.17 g, 4.54 mmol) was addedportionwise over 20 minutes. After the addition was complete, thereaction mixture was stirred at 5° C. for 2 hours. The reaction mixturewas quenched with water (10 mL) and concentrated under reduced pressure.The resulting aqueous residue was diluted with water (10 mL) andextracted with ethyl acetate (2×20 mL). The combined ethyl acetatelayers were washed with water (10 mL) and brine solution (10 mL), driedover anhydrous Na₂SO₄, and the solvent was removed to afford the crudeproduct, which was purified by column chromatography (silica gel 100-200mesh) using 20% ethyl acetate in petroleum ether as the eluent to affordIntermediate AH (440 mg, 62%) as a pale yellow solid.

¹H NMR (CDCl₃): δ 7.49-7.47 (m, 2H), 7.41-7.32 (m, 3H), 7.20 (d, J=9.12Hz; 1H), 7.06-7.05 (s, 1H), 7.00-6.97 (m, 1H), 6.88 (s, 1H), 5.11 (s,2H), 4.60 (t, J=7.25 Hz; 2H), 3.71 (s, 3H), 3.42 (t, J=7.25 Hz; 2H).Mass (M+H): 311.1.

Preparation of Intermediate AI

A suspension of Intermediate AH (430 mg, 1.381 mmol) and zinc powder(2.13 mg, 32.59 mmol) in methanol (57.0 mL) and 2N HCl (57.0 mL) wasstirred at 65° C. for 2 hours. The reaction mixture was basified (pH˜10)and filtered. The cake was washed with methanol (3×10 mL), and thecombined filtrate was concentrated under reduced pressure. The residuewas dissolved in 5% MeOH in chloroform (150 mL) and washed with water(20 mL). The organic layer was dried over anhydrous Na₂SO₄, and thesolvent was removed to afford the crude Intermediate AI (160 mg, 41%) asa brown gum. ¹H NMR (DMSO-d₆): δ 7.48-7.25 (m, 6H), 7.12-7.06 (m, 2H),6.86-6.83 (m, 1H), 5.09 (s, 2H), 3.68 (s, 3H), 2.79-2.68 (m, 4H). Mass(M+H): 281.1.

Preparation of Intermediate AJ

To a cold (0° C.) solution of Intermediate AI (150 mg, 0.535 mmol) andtriethylamine (0.15 mL, 1.07 mmol) in dichloromethane (10.0 mL) wasadded slowly a solution of methoxyacetyl chloride (0.06 mL, 0.64 mmol)in dichloromethane (2.0 mL) over 5 minutes. After the addition wascomplete, the reaction mixture was allowed to reach room temperature andstirred for 2 hours. The reaction mixture was diluted with water (10 mL)and extracted with dichloromethane (2×20 mL). The combineddichloromethane layer was washed with water (10 mL) and brine (10 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude product, which was purified by column chromatography (silica gel100-200 mesh) using 2% MeOH in chloroform as the eluent to affordIntermediate AJ (85 mg, 45%) as a brown gum. ¹H NMR (CDCl₃): δ 7.49-7.47(m, 2H), 7.41-7.30 (m, 3H), 7.21-7.13 (m, 2H), 6.99-6.96 (m, 1H), 6.87(s, 1H), 6.63 (bs, 1H), 5.11 (s, 2H), 3.87 (s, 2H), 3.72 (s, 3H),3.64-3.57 (m, 2H), 3.33 (s, 3H), 2.93 (t, J=6.84 Hz; 2H). Mass (M+H):353.1.

Preparation of Compound (21)

A suspension of Intermediate AJ (80 mg, 0.227 mmol) and 10% Pd/C (40 mg,dry) in MeOH (10.0 mL) was hydrogenated (40 psi H₂ pressure) at roomtemperature for 2 hours. The reaction mixture was filtered through aCelite bed, and the cake was washed with methanol (3×5 mL). The combinedfiltrates were concentrated under reduced pressure to give the crudeproduct, which was purified by column chromatography (silica gel 100-200mesh) using 2% MeOH in chloroform as the eluent to afford Compound (21)(30 mg, 50%) as a brown solid. ¹H NMR (CDCl₃): δ 7.15 (d, J=8.85 Hz;1H), 7.02 (s, 1H), 6.85-6.80 (m, 2H), 6.66 (bs, 5.02 (s, 1H), 3.88 (s,2H), 3.71 (s, 3H), 3.61-3.56 (m, 2H), 3.33 (s, 3H), 2.91 (t, J=6.97 Hz;2H). Mass (M+H): 262.9. IR (cm⁻¹): 3400, 2926, 1651, 1219, 1114, 771.HPLC purity (%): 93.49 (Max plot), 94.77 (254 nm), 97.19 (215 nm).

Synthesis of Compounds (22) and (23)

Compounds (22) and (23) were prepared according to the procedure shownin Scheme 16.

Preparation of Intermediate AL

To a cold (0° C.) suspension of 60% NaH (0.58 g, 14.51 mmol) in DMF(10.0 mL) was added slowly a solution of Intermediate AK (2.0 g, 12.40mmol) in DMF (5.0 mL) was added slowly for 5 minutes. The reaction wasthen stirred for 30 minutes, and iodomethane (2.06 g, 14.52 mmol) wasthen added to the reaction mixture. The reaction stirred at roomtemperature for 5 hours. The reaction mixture was quenched with ice coldwater (25 mL) and extracted with ethyl acetate (3×30 mL). The combinedethyl acetate layers were washed with water (2×20 mL) and brine (20 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude Intermediate AL which was purified by column chromatography(silica gel 100-200 mesh) using 12% ethyl acetate in petroleum ether asthe eluent to afford the product (1.25 g, 57%) as a brown solid. ¹H NMR(CDCl₃): δ 7.13 (d, J=8.78 Hz; 1H), 7.00 (s, 1H), 6.81-6.78 (dd, 1H),6.16 (s, 1H), 3.83 (s, 3H), 3.62 (s, 3H), 2.39 (s, 3H). Mass (M+H):176.0.

Preparation of Intermediates AM1 and AM2

General Procedure. POCl₃ (1.1 mmol) was added to DMF (2.0 mL) dropwiseat 0° C.-10° C. The resulting mixture was stirred for 30 minutes, cooledto 0° C., and a solution of Intermediate AK or Intermediate AL (1.0mmol) in DMF (2.0 mL) was added over 15 minutes. After the addition wascomplete, the reaction mixture was stirred at ambient temperature for 2hours. The reaction mixture was quenched with ice (25 g), poured intowater (30 mL), and basified (pH˜10) using a 1N NaOH solution. Themixture was extracted using ethyl acetate (3×20 mL), washed with water(2×10 mL) and brine (15 mL), and dried over anhydrous Na₂SO₄, andremoval of the solvent afforded Intermediate AM1 or AM2 (Table 10).

TABLE 10 AM1

Intermediate AK (2.0 g, 12.4 mmol) was reacted with POCl₃ (1.67 mL,13.64 mmol) in DMF (8.0 mL) to give Intermediate AM1 (1.7 g, 72%) as apale brown solid. ¹H NMR (CDCl₃): δ 10.15 (s, 1H), 8.35 (bs, 1H), 7.77(s, 1H), 7.21 (d, J = 8.78 Hz; 1H), 6.88 (dd, 1H), 3.88 (s, 3H), 2.72(s, 3II). Mass (M + H): 189.9. AM2

Intermediate AL (1.25 g, 7.14 mmol) was reacted with POCl₃ (0.74 mL,7.85 mmol) in DMF (10.0 mL) to give Intermediate AM2 (1.2 g, 82%) as apale brown solid. ¹H NMR (CDCl₃): δ 10.12 (s, 1H), 7.80 (s, 1H), 7.19(d, J = 8.85 Hz; 1H), 6.91 (dd, 1H), 3.89 (s, 3H), 3.68 (s, 3H), 2.66(s, 3H), Mass (M + H): 203.9.

Preparation of Intermediates AN1 and AN2

A suspension of Intermediate AM1 or AM2 (1.0 mmol), ammonium acetate(3.43 mmol) in nitromethane (80 mL) was stirred at 90° C. for 7 hours.The reaction mixture was concentrated under reduced pressure. Theresulting crude product was dissolved in ethyl acetate (100 mL), washedwith water (2×30 mL) and brine solution (25 mL), dried over anhydrousNa₂SO₄, and the solvent was removed to afford the crude Intermediate AN(Table 11).

TABLE 11 AN1

Intermediate AMI (1.7 g, 8.99 mmol) was reacted with ammonium acetate(2.3 g, 30.85 mmol) in nitromethane (120.0 ml,) to give Intermediate AN1(2.1 g, 98%) as a yellow solid. ¹H NMR (CDCl₃): δ 8.52 (bs, 1H), 8.33(d, J = 13.42 Hz; 1H), 7.71 (d, J = 13.42 Hz; 1H), 7.27-7.25 (m, 1H),7.11 (d, 1H), 6.91- 6.89 (m, 1H), 3.90 (s, 3H), 2.62 (s, 3H). Mass (M +H): 203.9. AN2

Intermediate AM2 (1.2 g, 5.91 mmol) was reacted with ammonium acetate(1.56 g, 20.27 mmol) in nitromethane (85.0 mL) to give Intermediate AN2(1.4 g, 96%) as a pale yellow solid. ¹H NMR (CDCl₃): δ 8.33 (d, J =13.15 Hz; 1H), 7.71 (d, J = 13.15 Hz; 1H), 7.26-7.23 (m, 1H), 7.12 (s,1H), 6.95-6.92 (m, 1H), 3.90 (s, 3H), 3.72 (s, 3H), 2.62 (s, 3H). Mass(M + H): 246.9.

Preparation of Intermediates AO1 and AO2

To a cold (0° C.) solution of Intermediate AN1 or AN2 (1.0 mmol) inmethanol and DMF (1:1; 35 mL), was added portionwise NaBH₄ (2.0 mmol)over 20 minutes. After the addition was complete, the reaction mixturewas allowed to stir at 10° C. for 2 hours. The reaction mixture wasquenched with water (10 mL) and concentrated under reduced pressure. Theresulting aqueous residue was diluted with water (20 mL) and extractedwith ethyl acetate (2×30 mL). The combined ethyl acetate layers werewashed with water (2×20 mL) and brine solution (20 mL), dried overanhydrous Na₂SO₄, and the solvent was removed to afford the crudeIntermediate AO (Table 12).

TABLE 12 AO1

Intermediate AN1 (1.0 g, 4.74 mmol) was reacted with NaBH₄ (360 mg, 9.48mmol) in MeOH (40.0 mL) to give Intermediate AO1 (1.1 g, crude) as apale brown gum. ¹H NMR (CDCl₃): δ 7.75 (bs, 1H), 7.17 (d, J = 8.70 Hz;1H), 6.90 (s, 1H), 6.81- 6.78 (m, 1H), 4.57 (t, J = 7.25 Hz; 2H), 3.86(s, 3H), 3.40 (t, J = 7.46 Hz, 2H), 2.37 (s, 3H). Mass (M + H): 235.1.AO2

Intermediate AN2 (1.3 g, 5.28 mmol) was reacted with NaBH₄ (400 mg,10.56 mmol) in MeOH (45.0 mL) to give Intermediate AO2 (1.4 g, crude) asa pale brown gum. ¹H NMR (CDCl₃): δ 7.15 (d, J = 8.70 Hz; 1H), 6.91 (s,1H), 6.85-6.84 (m, 1H), 4.55 (t, J = 7.46 Hz; 2H), 3.86 (s, 3H), 3.62(s, 3H), 3.42 (t, J = 7.46 Hz, 2H), 2.34 (s, 3H). Mass (M + H): 249.1.

Preparation of Intermediate AP1 and AP2

To a cold (−70° C.) solution of Intermediate AO (1.0 mmol) indichloromethane (˜30 mL) was added slowly BBr₃ (2.0 mmol). After theaddition was complete, the reaction mixture was allowed to reach 0° C.and stirred for 4 hours. The reaction mixture was diluted withdichloromethane (25 mL), washed with water (2×10 mL) and brine (20 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude Intermediate AP, each of which was purified by columnchromatography (silica gel 100-200 mesh) using 20% ethyl acetate inpetroleum ether as the eluent (Table 13).

TABLE 13 AP1

Intermediate AO1 (600 mg, 2.56 mmol) was reacted with BBr₃ (0.74 mL,5.12 mmol) in dichloromethane (20.0 mL) to give Intermediate AP1 (100mg, 18%) as a pale brown gum. ¹H NMR (CDCl₃): δ 7.75 (bs, 1H), 7.12 (d,J = 8.78 Hz; 1H), 6.86 (s, 1H), 6.71-6.68 (m, 1H), 4.73 (bs, 1H), 4.54(t, J = 7.31 Hz; 2H), 3.35 (t, J = 7.31 Hz, 2H), 2.36 (s, 3H). Mass (M +H): 221.0. AP2

Intermediate AO2 (600 mg, 2.41 mmol) was reacted with BBr₃ (0.47 mL,4.84 mmol) in dichloromethane (20.0 mL) to give Intermediate AP2 (75 mg,13%) as a pale brown gum. ¹H NMR (CDCl₃): δ 7.11 (d, J = 8.70 Hz; 1H),6.89 (s, 1H), 6.75-6.72 (m, 1H), 4.56-4.50 (m, 2H), 3.61 (s, 3H), 3.37(t, J = 7.46 Hz, 2H), 2.34 (s, 3H).

Preparation of Intermediates AQ1 and AQ2

A suspension of Intermediate AP (1.0 mmol) and 10% Pd/C (60% w/w, dry)in MeOH (30 mL) was hydrogenated (40 psi H₂ pressure) at 26° C. for 2hours. The reaction mixture was filtered, the cake was washed withmethanol (3×5 mL), and the combined filtrates were concentrated underreduced pressure to afford Intermediates AQ (Table 14), which was usedas such in the next step.

TABLE 14 AQ1

Intermediate AP1 (100 mg, 0.454 mmol) was hydrogenated with 10% Pd/C (60mg) in MeOH (20.0 mL) to give Intermediate AQ1 (80 mg, crude) as a palebrown gum. Mass (M + H): 191.1. AQ2

Intermediate AP2 (125 mg, 0.53 mmol) was hydrogenated with 10% Pd/C (70mg) in MeOH (20.0 mL) to give Intermediate AQ2 (108 mg, crude) as a palebrown gum. Mass (M + H): 205.1.

Preparation of Intermediates AR1 and AR2

To a cold (0° C.) solution of crude Intermediate AQ (1.0 mmol) andtriethylamine (2.2 mmol) in dichloromethane (20 mL), methoxyacetylchloride (2.2 mmol) was added slowly over 5 minutes. After the additionwas complete, the reaction mixture was allowed to reach room temperatureand stirred for 2 hours. The reaction mixture was diluted withdichloromethane (25 mL), washed with water (2×10 mL) and brine (20 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude Intermediate AR (Table 15), which was purified by columnchromatography (silica gel 100-200 mesh) using 20% ethyl acetate inpetroleum ether as the eluent.

TABLE 15 AR1

Intermediate AQ1 (80 mg, 0.42 mmol) was reacted with methoxyacetylchloride (0.04 mL, 0.42 mmol) and Et₃N (0.06 mL, 0.46 mmol) indichloromethane (15.0 mL) to give Intermediate AR1 (46 mg, 33%) as apale brown gum. ¹H NMR (CDCl₃): δ 7.87 (bs, 1H), 7.23-7.21 (m, 2H),6.87-6.84 (m, 1H), 6.58 (bs, 1H), 4.31 (s, 2H), 3.85 (s, 2H), 3.56 (s,3H), 3.53-3.48 (q, 2H), 3.31 (s, 3H), 2.90- 2.86 (m, 2H), 2.38 (s, 3H).Mass (M + H): 335.1. AR2

Intermediate AQ2 (108 mg, 0.53 mmol) was reacted with methoxyacetylchloride (0.11 mL, 1.16 mmol) and Et₃N (0.18 mL, 1.164 mmol) indichloromethane (15.0 mL) to give Intermediate AR2 (40 mg, 22%) as apale brown gum. ¹H NMR (CDCl₃): δ 7.23-7.21 (m, 2H), 6.91-6.88 (m, 1H),6.76 (bs, 1H), 4.31 (s, 2H), 3.85 (s, 2H), 3.66 (s, 3H), 3.51- 3.46 (m,2H), 3.31 (s, 3H), 2.91 (t, J = 7.05 Hz; 2H), 2.36 (s, 3H). Mass (M +H): 363.1.

Preparation of Compounds (22) and (23)

A suspension of Intermediate AR (1.0 mmol) and K₂CO₃ (1.1 mmol) inmethanol (20 mL) was stirred at 26° C. for 2 hours. The reaction mixturewas concentrated and the residue was diluted with water (20 mL) andextracted with ethyl acetate (2×20 mL). The combined ethyl acetatelayers were washed with brine (2×10 mL), dried over anhydrous Na₂SO₄,and concentrated to afford the crude product, which was purified byPREP-TLC using 70% ethyl acetate in petroleum ether as the eluent toafford the corresponding Compounds (22) and (23) (Table 16).

TABLE 16 (22)

Intermediate AR1 (46 mg, 0.14 mmol) was reacted with K₂CO₃ (20 mg, 0.15mmol) in MeOH (3.0 mL) to give Compound (22) (15 mg, 36%) as a palebrown gum. ¹H NMR (CDCl₃): δ 7.65 (bs, 1H), 7.13 (d, J = 8.70 Hz; 1H),6.94 (s, 1H), 6.70- 6.68 (m, 1H), 6.62 (bs, 1H), 4.79 (bs, 1H), 3.86 (s,2H), 3.54-3.49 (m, 2H), 3.32 (s, 3H), 2.86 (t, J = 6.84 Hz; 2H), 2.35(s, 3H). Mass (M + H): 263.1. IR (cm⁻¹): 3382, 2923, 1649, 1200, 1114,799. HPLC purity (%): 97.01 (Max plot), 95.28 (254 nm), 97.22 (215 nm).(23)

Intermediate AR2 (40 mg, 0.114 mmol) was reacted with K₂CO₃ (17 mg,0.126 mmol) in MeOH (3.0 mL) to give Compound (23) (14 mg, 38%) Palebrown solid. ¹H NMR (CDCl₃): δ 7.10 (d, J = 8.78 Hz; 1H), 6.96 (s, 1H),6.75-6.72 (m, 1H), 6.65 (bs, 1H), 4.93 (bs, 1H), 3.86 (s, 2H), 3.62 (s,3H), 3.51-3.46 (m, 2H), 3.31 (s, 3H), 2.89 (t, J = 6.83 Hz; 2H), 2.33(s, 3H). Mass (M + H): 277.1. IR (cm⁻¹): 3378, 2925, 1661, 1211, 1116,795. HPLC purity (%): 93.05 (Max plot), 80.02 (254 nm), 93.42 (215 nm).Synthesis of Compound (24)

Compound (24) was synthesized according to the procedure shown in Scheme17.

Preparation of Intermediate AS

A solution of Intermediate K (3.0 g, 13.45 mmol) and pyridine (1.8 mL,22.86 mmol) in dioxane (25.0 mL) was stirred at 65° C. for 1 hour. Asolution of chloroacetyl chloride (1.8 mL, 22.86 mmol) in dioxane (5.0mL) was then added dropwise. After the addition was complete, thereaction mixture was stirred for 1 hour. The reaction mixture wascooled, poured into cold ether (150 mL), and stirred. The resultingsolid was filtered, washed with cold ether (2×20 mL), and dried toafford crude Intermediate AS (1.6 g, 40%) as a yellow solid. ¹H NMR(DMSO-d₆): δ 12.04 (bs, 1H), 8.38 (s, 1H), 7.76 (s, 1H), 7.49-7.32 (m,6H), 6.96 (m, 1H), 5.13 (s, 2H), 4.84 (s, 2H). Mass (M+H):300.0.

Preparation of Intermediate AT

To a solution of Intermediate AS (1.6 g, 5.35 mmol) in acetone (80.0 mL)and water (40.0 mL), was added NaN₃ (800 mg, 1.23 mmol) and theresulting reaction mixture was stirred at 80° C. for 16 hours. Thereaction mixture was cooled to room temperature, diluted with water (100mL), and extracted with dichloromethane (2×100 mL). The combined organiclayers were washed with water (50 mL) and brine (30 mL), dried overanhydrous Na₂SO₄, and the solvent was removed to yield the crudeIntermediate AT. This material was washed with petroleum ether (2×10 mL)and dried to afford Intermediate AT (1.2 g, 73%) as a yellow solid.

¹H NMR (CDCl₃): δ 8.52 (bs, 1H), 7.99 (s, 1H), 7.85 (s, 1H), 7.50 (d,J=7.31 Hz; 1H), 7.41-7.32 (m, 4H), 7.05 (m, 1H), 5.16 (s, 2H), 4.37 (s,2H). Mass (M−H): 305.0. IR (cm⁻¹): 3190, 2924, 2103, 1641, 1259, 746.

Preparation of Intermediate AU

A suspension of Intermediate AT (1.2 g, 3.93 mmol) and 10% Pd/C (750 mg,dry) in MeOH (40.0 mL) was hydrogenated (60 psi H₂ pressure) at roomtemperature for 3 hours. The reaction mixture was filtered, and the cakewas washed with methanol (3×5 mL). The combined filtrates wereconcentrated under reduced pressure to afford Intermediate AU (750 mg,crude) as a brown solid, which was used without further purification inthe next step. Mass (M+H): 191.0.

Preparation of Intermediate AV

To a cold (0° C.) solution of Intermediate AU (500 mg, 2.63 mmol) andtriethylamine (1.09 mL, 7.89 mmol) in dichloromethane (20.0 mL) wasadded slowly methoxyacetyl chloride (430 mg, 3.94 mmol) over 5 minutes.After the addition was complete, the reaction mixture was allowed toreach room temperature and stirred for 2 hours. The reaction mixture wasdiluted with dichloromethane (50 mL), washed with water (2×20 mL) andbrine (20 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude Intermediate AV (800 mg, crude) which was used innext step without further purification.

Preparation of Compound (24)

A suspension of crude Intermediate AV (800 mg, 2.63 mmol) and K₂CO₃ (363mg, 2.63 mmol) in methanol (15.0 mL) was stirred at 26° C. for 1 hour.The reaction mixture was concentrated under reduced pressure; theresidue was diluted with water (20 mL) and extracted with ethyl acetate(2×20 mL). The combined ethyl acetate layers were washed with water (10mL) and brine (10 mL), dried over anhydrous Na₂SO₄, and the solvent wasremoved to afford the crude product. This material was purified bycolumn chromatography (100-200 mesh silica gel) using 10% MeOH inchloroform as the eluent to afford Compound (24) (190 mg, 30%) as a paleyellow solid. ¹H NMR (DMSO-d₆): δ 11.75 (bs, 1H), 9.01 (s, 1H), 8.30 (s,1H), 7.92 (m, 1H), 7.54 (s, 1H), 7.26 (d, J=8.70 Hz 1H), 6.71 (m, 1H),4.47 (d, J=5.39 Hz; 1H), 3.89 (s, 2H), 3.38 (s, 3H). Mass (M+H): 263.0.IR (cm⁻¹): 3259, 2930, 1661, 1614, 1215, 1122, 924. HPLC purity (%):93.7 (Max plot), 96.40 (254 nm), 94.59 (215 nm).

Synthesis of Compound (25)

Compound (25) can be synthesized according to the procedure shown inScheme 18. The aniline starting material can be transformed to thecorresponding arylhydrazine. Treatment of this arylhydrazineintermediate with 4-chlorobutyraldehyde diethyl acetal can afford therequisite indole intermediate. N-acylation followed by reduction of theC5 ester can result in the desired Compound (25).

Synthesis of Formula (II) CompoundsSynthesis of Compound (26)

Compound (26) was synthesized according to the procedure shown in Scheme19.

To a cold (0° C.) solution of Intermediate AW (250 mg, 1.79 mmol) andtriethylamine (0.3 mL, 2.13 mmol) in dichloromethane (5.0 mL) was addedslowly methoxyacetyl chloride (0.18 mL, 2.12 mmol) over 5 minutes. Afterthe addition was complete, the reaction mixture was allowed to reachroom temperature and stirred for 3 hours. The reaction mixture wasdiluted with dichloromethane (20 mL), washed with water (2×20 mL) andbrine (20 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude product, which was purified by column chromatography(silica gel 100-200 mesh) using 2% MeOH in chloroform as the eluent toafford Compound (26) (380 mg, 88%) as a pale brown oil. ¹H NMR(DMSO-d₆): δ 7.30-7.24 (m, 1H), 6.99-6.90 (m, 3H), 6.58 (bs, 1H), 3.87(s, 2H), 3.55 (q, J=13.26 Hz; J=7.09 Hz; 2H), 3.36 (s, 3H), 2.84 (t,J=7.04, Hz; 2H). Mass (M+H): 212.0. IR (cm⁻¹): 3418, 2934, 1671, 1534,1116, 783. HPLC purity (%): 97.37 (Max plot), 98.95 (215 nm).

Synthesis of Compound (27)

Compound (27) was prepared according to the procedure shown in Scheme20.

Preparation of Intermediate AY

To a solution of Intermediate AX (1.0 g, 4.99 mmol) in THF (20 mL) at 0°C. was added a solution of BH₃DMS (0.94 mL, 9.98 mmol). After theaddition was complete, the reaction mixture was stirred at 70° C. for 1hour. The reaction mixture was cooled, methanol (5.0 mL) was added, andthe mixture was refluxed for 30 minutes. Solvent from the reactionmixture was removed via distillation, and the residue was diluted withethyl acetate (30 mL), washed with water (2×15 mL) and brine (15 mL),dried over dried over anhydrous Na₂SO₄, and the solvent was removed toafford the crude Intermediate AY (720 mg, 77%) as an off white solid.This material was used in the next step without further purifications.¹H NMR (CDCl₃): δ 7.95 (s, 1H), 7.85 (d, J=7.88 Hz; 1H), 7.66 (d, J=7.88Hz, 1H), 7.56 (t, J=7.65 Hz; 1H), 4.80 (s, 2H), 3.06 (s, 3H). Mass(M+H): 187.0.

Preparation of Intermediate AZ

To a cold (0° C.) solution of Intermediate AY (2 g, 10.75 mmol) andtriethylamine (2.26 mL, 16.12 mmol) in dichloromethane (25 mL) was addedslowly methanesulfonyl chloride (1.08 mL, 13.85 mmol) over 5 minutes.After the addition was complete, the reaction mixture was allowed toreach room temperature and stirred for 16 hours. The reaction mixturewas quenched with cold water (10 mL), diluted with dichloromethane (20mL), washed with cold water (2×50 mL) and brine (20 mL), dried overanhydrous Na₂SO₄, and the solvent was removed to afford the crudeIntermediate AZ. This material was purified by column chromatography(silica gel 100-200 mesh) using 10% ethyl acetate in petroleum ether asthe eluent to afford the product (1.6 g, 73%) as a pale yellow oil. ¹HNMR (CDCl₃): δ 7.98 (s, 1H), 7.91 (d, J=7.80 Hz; 1H), 7.70 (d, J=7.80Hz, 1H), 7.59 (t, J=7.80 Hz; 1H), 4.65 (s, 2H), 3.07 (s, 3H). Mass(M+H): 205.0.

Preparation of Intermediate BA

To a cold solution of Intermediate AZ (500 mg, 2.45 mmol) in DMSO (5.0mL) at 0° C. was added sodium cyanide (240 mg, 4.89 mmol) portionwiseover 15 minutes. After the addition was complete, the reaction mixturewas allowed and stirred at 10° C. for 1 hour. Ice cold water (20 mL) wasadded to the reaction mixture. The reaction was then extracted withethyl acetate (3×20 mL), washed with water (20 mL) and brine (15 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude Intermediate BA. This material was purified by columnchromatography (silica gel 100-200 mesh) using 40% ethyl acetate inpetroleum ether as the eluent to afford the product (280 mg, 59%) as apale brown solid. ¹H NMR (CDCl₃): δ 7.95-7.91 (m, 2H), 7.69-7.61 (m,2H), 3.86 (s, 2H), 3.07 (s, 3H). Mass (M−H): 194.0. IR (cm⁻¹): 2927,2249, 1300, 1144, 964, 761.

Preparation of Compound (27)

A suspension of Intermediate BA (250 mg, 1.28 mmol) and Raney-Ni (100mg, wet) in methanolic NH₃ (5.0 mL) was hydrogenated by bubbling H₂ at10° C. for 3 hours. The reaction mixture was filtered, the cake waswashed with methanol (3×10 mL), and the combined filtrate wasconcentrated under reduced pressure. The resulting oily residue wasdissolved in ethyl acetate (2.0 mL), cooled in ice, treated with EtOAcand HCl, and stirred for 10 minutes. The resulting solid was filtered,washed with ethyl acetate (3×5 mL), and dried to afford Compound(27).HCl (150 mg, 50%) as an off white solid. ¹H NMR (DMSO-d₆): δ 7.91(bs, 2H), 7.83-7.81 (m, 2H), 7.64-7.62 (m, 2H), 3.21 (s, 3H), 3.11-3.01(m, 2H), 2.99-2.97 (m, 2H). Mass (M+H): 200.0. IR (cm⁻¹): 3402, 3034,1601, 1290, 1141, 965, 767, 532. HPLC purity (%): 99.92 (Max plot),99.90 (215 nm).

Preparation of Compound (28)

Compound (28) was prepared according to the procedure shown in Scheme21.

Preparation of Intermediate BC

To a cold solution of Intermediate BB (2 g, 9.25 mmol) in DMSO (20.0 mL)at 0° C. was added sodium cyanide (900 mg, 18.36 mmol) portionwise over15 minutes. After the addition was complete, the reaction mixture wasallowed and stirred at 10° C. for 3 hours. Ice cold water was added tothe reaction mixture (30 mL), and the reaction mixture was extractedwith ethyl acetate (3×25 mL), washed with water (20 mL) and brine (15mL), dried over dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude product. The mixture was purified by columnchromatography (silica gel 100-200 mesh) using 40% ethyl acetate inpetroleum ether as the eluent to afford Intermediate BC (800 mg, 53%) asa brown gum. ¹H NMR (CDCl₃): δ 8.23-8.21 (m, 2H), 7.72 (d, J=7.80 Hz,1H), 7.62 (m, 1H), 3.89 (s, 2H). Mass (M−H): 161.0.

Preparation of Intermediate BD

To a stirred solution of NH₄Cl (1.1 g, 19.74 mmol) in H₂O (16 mL) wasadded Fe powder (1.01 g, 18.08 mmol) followed by Intermediate BC (800mg, 4.23 mmol) in a mixture of THF (8.0 mL) and MeOH (8.0 mL) slowly atroom temperature. The reaction was then stirred for 3 h at 60° C. Thereaction mixture was cooled to room temperature, diluted with ethylacetate (100 mL), and filtered through a Celite bed. The organic layerwas washed with water (2×25 mL) and brine solution (20 mL), dried overanhydrous Na₂SO₄, and evaporated to afford the crude product. Thismaterial was purified by column chromatography (silica gel 100-200 mesh)using 40% ethyl acetate in petroleum ether as the eluent to affordIntermediate BD (520 mg, 80%) as a brown gum. ¹H NMR (CDCl₃): δ 7.14 (d,J=7.67 Hz, 1H), 7.68-6.62 (m, 3H), 3.74 (bs, 2H), 3.65 (s, 2H). Mass(M+H): 238.0.

Preparation of Intermediate BE

To a cold (0° C.) solution of Intermediate BD (500 mg, 3.78 mmol) andtriethylamine (0.63 mL, 4.48 mmol) in dichloromethane (10 mL) was addedslowly methanesulfonyl chloride (0.35 mL, 4.49 mmol) over 5 minutes.After the addition was complete, the reaction mixture was allowed toreach room temperature and stirred for 2 hours. The reaction mixture wasdiluted with dichloromethane (10 mL), washed with water (2×20 mL) andbrine (10 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude product. This material was purified by columnchromatography (silica gel 100-200 mesh) using 15% ethyl acetate inpetroleum ether as the eluent to afford Intermediate BE (300 mg, 38%) asa brown gum. ¹H NMR (CDCl₃): δ 7.40-7.34 (m, 1H), 7.20-7.16 (m, 2H),6.63 (bs, 1H), 3.76 (s, 2H), 3.04 (s, 3H). Mass (M−H): 187.0.

Preparation of Intermediate BF

A suspension of Intermediate BE (100 mg, 0.47 mmol) and Raney-Ni (20 mg,wet) in methanolic NH₃ (5.0 mL) was hydrogenated by bubbling H₂ at 10°C. for 3 hours. The reaction mixture was filtered, and the cake waswashed with methanol (3×10 mL). The combined filtrates were concentratedunder reduced pressure to afford Intermediate BF (80 mg, crude) as apale brown oil, which was used in the next step without furtherpurification.

Preparation of Compound (28)

To a cold (0° C.) solution of crude Intermediate BF (30 mg, 0.14 mmol)and triethylamine (0.02 mL, 0.14 mmol) in dichloromethane (4.0 mL) wasadded slowly a solution of methoxyacetyl chloride (0.03 mL, 0.13 mmol)in dichloromethane (1.0 mL) over 5 minutes. After the addition wascomplete, the reaction mixture was allowed to reach room temperature andstirred for 2 hours. The reaction mixture was diluted withdichloromethane (10 mL), washed with water (2×10 mL) and brine (10 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude product. This material was purified by column chromatography(silica gel 100-200 mesh) using 23% ethyl acetate in petroleum ether asthe eluent to afford Compound (28) (29 mg, 72%) as a pale brown gum. ¹HNMR (CDCl₃): δ 7.31-7.25 (m, 2H), 7.09-7.03 (m, 2H), 6.58 (bs, 1H), 6.50(bs, 1H), 3.87 (s, 2H), 3.59-3.53 (q, 2H), 3.37 (s, 3H), 2.84 (t, J=7.11Hz; 2H). Mass (M+H): 286.9. IR (cm⁻¹): 3401, 2927, 1655, 1328, 1149,976, 763, 515. HPLC purity (%): 94.51 (Max plot), 92.11 (215 nm).

Synthesis of Compounds (29) and (30)

Compounds (29) and (30) were prepared according to the procedure inScheme 22.

Preparation of Intermediate BH

A suspension of Intermediate BG (5 g, 27.02 mmol) and ammonium acetate(4.57 g, 59.45 mmol) in nitromethane (150.0 mL) was stirred at 90° C.for 1 hour. The reaction mixture was concentrated under reducedpressure, and the resulting crude material was dissolved in ethylacetate (100 mL), washed with water (2×30 mL) and brine solution (25mL), dried over anhydrous Na₂SO₄, and the solvent was removed to affordthe crude product. This material was purified by column chromatography(silica gel 100-200 mesh) using 2% ethyl acetate in petroleum ether asthe eluent to afford Intermediate BH (2.2 g, 36%) as a yellow solid. ¹HNMR (CDCl₃): δ 7.93 (d, J=13.66 Hz, 1H), 7.70 (s, 1H), 7.62 (d, J=8.00Hz, 1H), 7.56 (d, J=13.66 Hz, 1H), 7.48 (d, J=7.61 Hz, 1H), 7.34 (s,J=7.90 Hz, 1H). Mass (M−2H), M: 226.9, 228.9.

Preparation of Intermediate BI

To a cold (0° C.) solution of Intermediate BH (2 g, 8.77 mmol) inmethanol (30 mL) at 0° C. was added NaBH₄ (0.4 g, 10.52 mmol)portionwise over 15 minutes. After the addition was complete, thereaction mixture was allowed to stir at 10° C. for 1 hour. The reactionmixture was quenched with water (10 mL) and concentrated under reducedpressure. The resulting aqueous residue was diluted with water (25 mL)and extracted with ethyl acetate (2×50 mL). The combined ethyl acetatelayers were washed with water (30 mL) and brine solution (25 mL), driedover anhydrous Na₂SO₄, and the solvent was removed to afford the crudeproduct. This material was purified by column chromatography (silica gel100-200 mesh) using 5% ethyl acetate in petroleum ether as the eluent toafford Intermediate BI (1.5 g, 74%) as pale yellow solid. ¹H NMR(CDCl₃): δ 7.39 (d, J=10.78 Hz, 1H), 7.37 (s, 1H), 7.22-7.15 (m, 2H),4.61 (t, J=7.46 Hz, 2H), 3.29 (t, J=7.03 Hz, 2H). Mass (M−2H), M: 227.9,229.9.

Preparation of Intermediate BJ

A suspension of Intermediate BI (350 mg, 15.21 mmol) and zinc powder(300 mg, 4.56 mmol) in methanol (50.0 mL) and 2N HCl (50.0 mL) wasstirred at 65° C. for 1 hour. The reaction mixture was filtered, and thecake was washed with methanol (3×10 mL). The combined filtrates wereconcentrated under reduced pressure, and the residue was dissolved indichloromethane, dried over anhydrous Na₂SO₄, and the solvent wasremoved to afford the crude Intermediate BJ (1 g, crude), which was usedin the next step without further purification.

Preparation of Intermediate BK

To a cold (0° C.) solution of crude Intermediate BJ (300 mg, 1.50 mmol)and triethylamine (0.42 mL, 3.01 mmol) in dichloromethane (15.0 mL) wasadded slowly a solution of methoxyacetyl chloride (0.15 mL, 1.65 mmol)in dichloromethane (2.0 mL) over 5 minutes. After the addition wascomplete, the reaction mixture was allowed to reach room temperature andstirred for 2 hours. The reaction mixture was diluted withdichloromethane (10 mL), washed with water (2×20 mL) and brine (10 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude product. This material was purified by column chromatography(silica gel 100-200 mesh) using 1% MeOH in chloroform as the eluent toafford Intermediate BK (200 mg, 60%) as a pale brown solid. ¹H NMR(CDCl₃): δ 7.38-7.36 (m, 2H), 7.20-7.12 (m, 2H), 6.55 (bs, 1H), 3.87 (s,2H), 3.56-3.51 (m, 2H), 3.37 (s, 3H), 2.81 (t, J=7.12 Hz, 2H). Mass (M,M+H): 271.9, 273.9.

Preparation of Compound (29)

A suspension of Intermediate BK (300 mg, 1.10 mmol) and CuCN (200 mg,2.20 mmol) in DMSO (4.0 mL) was stirred in a sealed tube at 165° C. for20 hours. The reaction mixture was cooled to room temperature, dilutedwith water (10 mL), and extracted with ethyl acetate (2×20 mL). Thecombined ethyl acetate layers were washed with water (2×10 mL) and brine(10 mL), dried over anhydrous Na₂SO₄, and the solvent was removed toafford the crude product. This material was purified by columnchromatography (silica gel 100-200 mesh) using 2% MeOH in chloroform asthe eluent to afford Compound (29) (100 mg, 41.5%) as a pale brown gum.¹H NMR (CDCl₃): δ 7.55-7.42 (m, 4H), 6.6 (bs, 1H), 3.88 (s, 2H),3.58-3.53 (q, 2H), 3.38 (s, 3H), 2.89 (t, J=7.31 Hz; 2H). Mass (M−H):217. IR (cm⁻¹): 3412, 2928, 2230, 1665, 1537, 1116, 798, 691. HPLCpurity (%): 95.33 (Max plot), 92.55 (215 nm).

Preparation of Compound (30)

To a cold (0° C.) solution of Compound (29) (100 mg, 0.45 mmol), 3N NaOH(3.0 mL) in ethanol (3.0 mL) at 0° C. was added added H₂O₂ (30% inwater; 0.05 mL). After the addition was complete, the reaction mixturewas allowed to reach room temperature and stirred for 20 hours. Thereaction mixture was concentrated, and the resulting aqueous residue wasdiluted with dichloromethane (50 mL), washed with water (2×10 mL) andbrine (10 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude product. This material was purified by columnchromatography (silica gel 100-200 mesh) using 5% MeOH in chloroform asthe eluent to afford Compound (30) (40 mg, 37%) as an off white solid.¹H NMR (CDCl₃): δ 7.70-7.67 (m, 2H), 7.40-7.38 (m, 2H), 6.58 (bs, 1H),6.2 (bs, 1H), 5.6 (bs, 1H), 3.86 (s, 2H), 3.63-3.60 (q, 2H), 3.58 (s,3H), 2.91 (t, J=7.04 Hz; 2H). Mass (M+H): 237.1. IR (cm⁻¹): 3339, 3162,1661, 1543, 1199, 1120, 690. HPLC purity (%): 95.95 (Max plot), 95.29(215 nm).

Preparation of Compound (31)

Compound (31) was prepared according to the procedure shown in Scheme23.

Preparation of Intermediate BM

To a solution of Intermediate BL (5.0 g, 33.29 mmol) and benzoylperoxide (0.4 g, L66 mmol) in CCl₄ (60.0 mL) was added NBS (5.75 g,33.29 mmol). The reaction mixture was stirred at 70° C. for 4 hours. Thereaction mixture was filtered, and the filtrate was concentrated toobtain the crude product. This material was purified by columnchromatography (silica gel 100-200 mesh) using 1% ethyl acetate inpetroleum ether as the eluent to afford Intermediate BM (6.8 g, 87%) aspale yellow oil. ¹H NMR (CDCl₃): δ 8.07 (s, 1H), 8.00-7.96 (m, 1H),7.60-7.58 (m, 1H), 7.43 (t, J=7.67 Hz, 1H), 4.52 (s, 2H), 3.93 (s,31-1).

Preparation of Intermediate BN

To a cold solution of Intermediate BM (7.2 g, 31.44 mmol) in DMSO (35.0mL) at 0° C. was added a sodium cyanide (3.0 g, 62.88 mmol) portionwiseover 15 minutes. After the addition was complete, the reaction mixturewas allowed to stir at 10° C. for 3 hours. Ice cold water was added tothe reaction mixture (50 mL), and the reaction was extracted with ethylacetate (3×50 mL), washed with water (2×25 mL) and brine (25 mL), driedover anhydrous Na₂SO₄, and the solvent was removed to afford the crudeproduct. This material was purified by column chromatography (silica gel100-200 mesh) using 10% ethyl acetate in petroleum ether as the eluentto afford Intermediate BN (2.8 g, 51%) as a pale brown liquid. ¹H NMR(CDCl₃): δ 9.44-9.42 (m, 2H), 8.90-8.78 (m, 2H), 4.63 (s, 3H), 4.49 (s,2H). Mass (M−H): 174.1.

Preparation of Intermediate BO

To a cold (0° C.) solution of Intermediate BN (500 mg, 2.85 mmol) in THF(25.0 mL) was added NaBH₄ (216 mg, 5.71 mmol), and the reaction stirredat 80° C. for 15 minutes. Methanol (8.0 mL) was then added to thereaction mixture at 80° C. until the effervescence eased. The reactionwas then stirred for approximately 16 hours. The reaction mixture wasthen quenched with water (10 mL) and concentrated under reducedpressure. The resulting aqueous residue was diluted with water (25 mL)and extracted with ethyl acetate (2×50 mL). The combined ethyl acetatelayers were washed with water (25 mL) and brine solution (25 mL), driedover anhydrous Na₂SO₄, and the solvent was removed to afford the crudeproduct. This material was purified by column chromatography (silica gel100-200 mesh) using 12% ethyl acetate in petroleum ether as the eluentto afford Intermediate BO (410 mg, 95%) as as pale yellow oil. ¹H NMR(CDCl₃): δ 7.40-7.32 (m, 3H), 7.27 (s, 1H), 4.72 (d, J=5.66 Hz, 2H),3.76 (s, 2H), 1.72 (t, J=5.76 Hz, 1H). Mass (M−H): 146.1.

Preparation of Intermediate BP

A suspension of Intermediate BO (200 mg, 1.32 mmol) and Raney-Ni (50 mg,wet) in methanolic NH₃ (6.0 mL) was hydrogenated by bubbling H₂ at 10°C. for 3 hours. The reaction mixture was filtered, and the cake waswashed with methanol (3×10 mL). The combined filtrates were concentratedunder reduced pressure to afford Intermediate BP (200 mg, crude), as apale brown gum. ¹H NMR (CDCl₃): δ 7.30-7.21 (m, 4H), 4.69 (s, 2H), 3.49(s, 2H), 2.9 (bs, 2H), 4.80 (s, 2H). Mass (M+H): 152.0.

Preparation of Intermediate BQ

To a cold (0° C.) solution of Intermediate BP (200 mg, 1.32 mmol) andtriethylamine (0.27 mL, 1.92 mmol) in dichloromethane (10.0 mL) wasadded slowly methoxyacetyl chloride (0.18 mL, 1.96 mmol) over 5 minutes.After the addition was complete, the reaction mixture was allowed toreach room temperature and stirred for 3 hours. The reaction mixture wasdiluted with dichloromethane (10 mL), washed with water (2×20 mL) andbrine (10 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude product. This material was purified by columnchromatography (silica gel 100-200 mesh) using 5-10% ethyl acetate inpetroleum ether as the eluent to afford Intermediate BQ (250 mg, 64%) asa pale brown gum. ¹H NMR (CDCl₃): δ 7.33-7.17 (m, 4H), 6.56 (bs, 1H),5.18 (s, 2H), 4.08 (s, 2H), 3.87 (s, 2H), 3.58-3.53 (m, 2H), 3.46 (s,3H), 3.36 (s, 3H), 2.85 (t, J=7.07 Hz; 2H). Mass (M+H): 295.9.

Preparation of Compound (31)

A suspension of Intermediate BQ (250 mg, 0.84 mmol) and K₂CO₃ (130 mg,0.94 mmol) in methanol (3.0 mL) was stirred at 26° C. for 1 hour. Thereaction mixture was concentrated under reduced pressure; the residuewas then diluted with water (20 mL) and extracted with ethyl acetate(2×20 mL). The combined ethyl acetate layers were washed with water (10mL) and brine (10 mL), dried over anhydrous Na₂SO₄, and the solvent wasremoved to afford the crude product. This material was purified bycolumn chromatography (100-200 mesh silica gel) using 20% ethyl acetatein petroleum ether as the eluent to afford Compound (31) (120 mg, 63%)as a pale brown solid. ¹H NMR (CDCl₃): δ 7.32-7.22 (m, 3H), 7.13 (d,J=7.41 Hz; 1H), 6.56 (bs, 1H), 4.67 (s, 2H), 3.85 (s, 2H), 3.58-3.53 (m,3H), 3.35 (s, 3H), 2.84 (t, J=7.12 Hz; 2H). Mass (M+H): 223.9. IR(cm⁻¹): 3401, 2931, 1658, 1540, 1116, 791. HPLC purity (%): 98.9 (Maxplot), 96.92 (254 nm), 97.11 (215 nm).

Synthesis of Compound (32)

Compound (32) was synthesized according to the procedure shown in Scheme24.

Preparation of Intermediate BS

A suspension of Intermediate BR (1 g, 8.19 mmol) and ammonium acetate(1.38 g, 18.03 mmol) in nitromethane (70.0 mL) was stirred at 90° C. for1 hour. The reaction mixture was concentrated under reduced pressure,the resulting crude material was dissolved in ethyl acetate (50 mL),washed with water (2×20 mL) and brine solution (25 mL), dried overanhydrous Na₂SO₄, and the solvent was removed to afford the crudeproduct. This material was purified by column chromatography (silica gel100-200 mesh) using 10% ethyl acetate in petroleum ether as the eluentto afford Intermediate BS (550 mg, 40.6%) as yellow solid. ¹H NMR(CDCl₃): δ 7.95 (d, J=13.68 Hz; 1H), 7.55 (d, J=13.68 Hz; 1H), 7.13 (d,J=7.87 Hz, 1H), 7.01-6.95 (m, 2H), 4.97 (s, 2H). Mass (M−H): 164.0.

Preparation of Intermediate BT

To a cold (0° C.) solution of Intermediate BS (350 mg, 2.12 mmol) inmethanol (3.5 mL) at 0° C. was added portionwise NaBH₄ (100 mg, 2.54mmol) over 5 minutes. After the addition was complete, the reactionmixture was allowed to stir at 10° C. for 1 hour. The reaction mixturewas quenched with water (5 mL) and concentrated under reduced pressure.The resulting aqueous residue was diluted with water (15 mL) andextracted with ethyl acetate (2×20 mL). The combined ethyl acetatelayers were washed with water (10 mL) and brine solution (15 mL), driedover anhydrous Na₂SO₄, and the solvent was removed to afford the crudeproduct. This material was purified by column chromatography (silica gel100-200 mesh) using 10% ethyl acetate in petroleum ether as the eluentto afford Intermediate BT (200 mg, 56.4%) as a pale yellow solid. ¹H NMR(CDCl₃): δ 7.19 (s, J=7.90 Hz; 1H), 6.77-6.72 (m, 2H), 6.68 (s, 1H),4.59 (t, J=7.32 Hz, 2H), 3.27 (t, J=7.32 Hz). Mass (M−H): 166.0.

Preparation of Intermediate BU

A suspension of Intermediate BT (150 mg, 0.89 mmol) and 10% Pd/C (25 mg,dry) in MeOH (1.0 mL) was hydrogenated by bubbling H₂ at 10° C. for 3hours. The reaction mixture was filtered, and the cake was washed withmethanol (3×5 mL). The combined filtrates were concentrated underreduced pressure. The obtained gummy material was dissolved in ethylacetate (1 mL), treated with EtOAc and HCl (0.5 mL). The reactionstirred for 10 minutes and was then concentrated to afford the HCl saltof Intermediate BU(200 mg, crude) as a pale brown gum. This material wasused without further purification in the next step.

Preparation of Intermediate BV

To a cold (0° C.) solution of Intermediate BU (200 mg, 1.15 mmol) andtriethylamine (0.323 mL, 2.3 mmol) in dichloromethane (3.0 mL) was addedslowly methoxyacetyl chloride (0.136 mL, 1.26 mmol) over 5 minutes.After the addition was complete, the reaction mixture was allowed toreach room temperature and stirred for 2 hours. The reaction mixture wasdiluted with dichloromethane (10 mL), washed with water (2×20 mL) andbrine (10 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude product. This material was purified by columnchromatography (silica gel 100-200 mesh) using 2% MeOH in chloroform asthe eluent to afford Intermediate BV (20 mg, 61.7%) as a pale brown gum.¹H NMR (CDCl₃): δ 7.33 (t, J=7.86 Hz; 1H), 7.09 (d, J=7.64 Hz; 1H),7.00-6.97 (m, 2H), 6.56 (bs, 1H), 4.28 (s, 2H), 3.87 (s, 2H), 3.59-3.54(m, 5H), 3.35 (s, 3H), 2.85 (t, J=7.04 Hz; 2H). Mass (M+H): 282.0.

Preparation of Compound (32)

A suspension of Intermediate BV (200 mg, 0.71 mmol) and K₂CO₃ (108 mg,0.78 mmol) in methanol (2.0 mL) was stirred at 26° C. for 1 hour. Thereaction mixture was concentrated under reduced pressure; the residuewas then diluted with water (10 mL) and extracted with ethyl acetate(2×20 mL). The combined ethyl acetate layers were washed with water (10mL) and brine (10 mL), dried over anhydrous Na₂SO₄, and the solvent wasremoved to afford the crude product. This material was purified bycolumn chromatography (100-200 mesh silica gel) using 4% MeOH inchloroform as the eluent to afford Compound (32) (80 mg, 53.7%) as apale brown gum. ¹H NMR (CDCl₃): δ 7.17 (t, J=8.30 Hz; 1H), 6.77 (d,J=7.81 Hz; 1H), 6.71-6.69 (m, 2H), 6.55 (bs, 1H), 4.85 (s, 1H), 3.87 (s,2H), 3.58-3.53 (m, 3H), 3.35 (s, 3H), 2.79 (t, J=7.08 Hz; 2H). Mass(M+H): 210.0. IR (cm⁻¹): 3392, 2936, 1658, 1542, 1455, 1116, 783. HPLCpurity (%): 94.43 (Max plot), 94.16 (215 nm).

Synthesis of Compounds (33), (34), and (35)

Compounds (33)-(35) were synthesized according to the procedure shown inScheme 25.

Preparation of Intermediate BX

To a cold suspension of NaBH₄ (1.5 mmol) in THF (30 mL) at 0° C.,Intermediate BW (1.0 mmol) was added portionwise over 15 minutes. Afterthe addition was complete, the reaction mixture was allowed to stir atroom temperature for 2 hours. To the reaction mixture was added slowly asolution of BF₃.O(Et)₂ (2.0 mmol) in THF (10 mL) over 3 hours. After theaddition was complete, the reaction mixture was stirred at roomtemperature for 20 hours. The reaction mixture was quenched with 1.5NHCl (10 mL) and MeOH (20 mL) then concentrated. The obtained aqueousresidue was basified (pH˜10) with 1N NaOH solution and extracted withethyl acetate (3×30 mL). The combined ethyl acetate layers were washedwith brine solution (2×20 mL), dried over anhydrous Na₂SO₄, and thesolvent was removed to afford the crude Intermediate BX (Table 17),which was used in the next step without further purification.

TABLE 17 BX1

Intermediate BW1 (1.5 g, 9.52 mmol) was reacted with NaBH4 (1.08 g,28.57 mmol) and BF₃•O(Et)₂ (4.8 mL, 38.09 mmol) in THF (100 mL) to giveIntermediate BX1 (1.3 g, crude) as a colorless thick oil. ¹H NMR(CDCl₃): δ 7.66 (t, J = 7.67 Hz; 1H). 7.25 (d, J = 7.87 Hz; 2H), 4.75(s, 2H), 3.41 (bs, 1H). Mass (M + H): 144.0. BX2

Intermediate BW2 (2.5 g, 15.87 mmol) was reacted with NaBH4 (0.9 g,23.80 mmol) and BF₃•O(Et)₂ (3.9 mL, 31.74 mmol) in THF (100 mL) to giveIntermediate BX2 (3.0 g, crude) as a colorless thick oil. ¹H NMR(CDCl₃): δ 8.35 (d, J = 4.87 Hz 1H), 7.36 (s, 1H), 7.21 (d, J = 5.85 Hz;2H), 4.75 (d, J = 5.36 Hz; 2H). Mass (M + H): 144.0.

Preparation of Intermediate BY

To a cold solution of Intermediate BX (1.0 mmol) in dichloromethane (15mL) at 0° C. was added slowly thionyl chloride (1.0 mmol) over 15minutes. After the addition was complete, the reaction mixture wasallowed to stir at room temperature for 20 hours. The reaction mixturewas cooled, and ice cold water was added (30 mL). The mixture wasextracted with dichloromethanc (3×50 mL), washed with water (25 mL) andbrine (25 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude Intermediate BY (Table 18), which was purified bycolumn chromatography (silica gel 100-200 mesh) using 20% ethyl acetatein petroleum ether as the eluent.

TABLE 18 BY1

Intermediate BX1 (1.3 g, 9.09 mmol) was reacted with thionyl chloride(0.66 mL, 13.98 mmol) in dichloromethane (30 mL) to give IntermediateBY1 (800 mg, 57%) as a pale brown solid. ¹H NMR (CDCl₃): δ 7.69 (t, J =7.87 Hz; 1H), 7.43 (d, J = 7.46 Hz; 1H), 7.28 (d, J = 7.87 Hz; 1H), 4.63(s, 2H). Mass (M + H): 161.9. BY2

Intermediate BX2 (2.0 g, 13.98 mmol) was reacted with thionyl chloride(1.0 mL, 13.98 mmol) in dichloromethane (30 mL) to give Intermediate BY2(1.5 g, 68%) as a pale brown solid. ¹H NMR (CDCl₃): δ 8.39 (d, J = 4.97Hz; 1H), 7.38 (s, 1H), 7.25 (d, J = 4.56 Hz; 1H), 4.52 (s, 2H). Mass(M + H): 162.0.

Preparation of Intermediate BZ

To a cold solution of Intermediate BY (1.0 mmol) in DMSO (10 mL) at 0°C. was added sodium cyanide (2.0 mmol) portionwise over 15 minutes.After the addition was complete, the reaction mixture was allowed tostir at 10° C. for 2 hours. Ice cold water was added to the reactionmixture (30 mL), and the mixture was extracted with ethyl acetate (3×50mL), washed with water (25 mL) and brine (25 mL), dried over anhydrousNa₂SO₄, and the solvent was removed to afford the crude Intermediate BZ(Table 19), which was purified by column chromatography (silica gel100-200 mesh) using 10% ethyl acetate in petroleum ether as the eluent.

TABLE 19 BZ1

Intermediate BY1 (800 mg, 4.93 mmol) was reacted with sodium cyanide(484 mg, 9.87 mmol) in DMSO (8 mL) to give Intermediate BZ1 (400 mg,53%) as a pale brown solid, ¹H NMR (CDCl₃): δ 7.73 (t, J= 7.81 Hz; 1H),7.42 (d, J = 7.61 Hz; 1H), 7.33 (d, J = 8.00 Hz; 1H), 3.93 (s, 2H). Mass(M + H): 152.9. IR (cm⁻¹): 3079.79, 2923.5, 2252.12, 1439.39 and 789.42.BZ2

Intermediate BY2 (1.5 g, 9.25 mmol) was reacted with sodium cyanide (0.9g, 18.51 mmol) in DMSO (15 mL) to give Intermediate BZ2 (300 mg, 16.6%)as a pale brown solid. ¹H NMR (CDCl₃): δ 8.43 (d, J = 5.07 Hz; 1H), 7.36(s, 1H), 7.24 (d, J = 5.07 Hz; 1H), 3.78 (s, 2H). Mass (M + H): 153.0.IR (cm⁻¹): 2923.5, 2245.9, 1595.3, 1404.6 and 825.9. BZ3

Intermediate BY3 (1.5 g, 9.25 mmol) was reacted with sodium cyanide (0.9g, 18.51 mmol) in DMSO (15 mL) to give Intermediate BZ3 (800 mg, 57%) asa pale brown solid. ¹H NMR (CDCl₃): δ 8.37 (s, 1H), 7.68 (d, J = 8.29Hz; 1H), 7.39 (s, J = 8.29 Hz; 1H), 7.25 (d, J = 4.56 Hz; 2H), 3.77 (s,2H). Mass (M + H): 153.0. IR (cm⁻¹): 2923.5, 1439.3, 1108.8 and 789.4.

Preparation of Intermediate CA

To a cold solution of Intermediate BZ (1.0 mmol) in THF (30 mL) at 0° C.was BH₃.DMS (9.0 mmol) was added slowly over 5 minutes. After theaddition was complete, the reaction mixture was allowed to reach roomtemperature and stirred for 20 hours. The reaction mixture was cooled inice and then quenched with MeOH (5 mL). The reaction was then refluxedfor 1 hour and concentrated. The residue was dissolved in ethyl acetate(50 mL), washed with water (2×10 mL) and brine solution (15 mL), driedover anhydrous Na₂SO₄, and the solvent was removed to afford the crudeIntermediate CA (Table 20), which was in the next step without furtherpurification.

TABLE 20 CA1

Intermediate BZ1 (360 mg, 2.36 mmol) was reacted with BH₃•DMS (2.0 mL,21.24 mmol) in THF (12 mL) to give Intermediate CA1 (250 mg, crude) as apale brown gum. Mass (M + H): 157.0. CA2

Intermediate BZ2 (350 mg, 2.30 mmol) was reacted with BH₃•DMS (1.9 mL,20.72 mmol) in THF (10 mL) to give Intermediate CA2 (350 mg, crude) as apale brown gum Mass (M + H): 157.0. CA3

Intermediate BZ3 (1.0 g, 6.57 mmol) was reacted with BH₃•DMS (5.6 mL,59.13 mmol) in THF (30 mL) to give Intermediate CA3 (1 g, crude) as apale brown gum. Mass (M + H): 157.0.

Preparation of Intermediate CB

To a cold (0° C.) solution of Intermediate CA (1.0 mmol) andtriethylamine (2.0 mmol) in dichloromethane (20 mL) was added slowlymethoxyacetyl chloride (1.1 mmol) over 5 minutes. After the addition wascomplete, the reaction mixture was allowed to reach room temperature andstirred for 4 hours. The reaction mixture was diluted withdichloromethane (10 mL), washed with water (2×15 mL) and brine (10 mL),dried over anhydrous Na₂SO₄, and the solvent was removed to afford thecrude Intermediate CB (Table 21), which was purified by PREP-TLC plateusing 5% MeOH in ethyl acetate as the eluent.

TABLE 21 CB1

Intermediate CA1 (370 mg, 2.37 mmol) was reacted with methoxyacetylchloride (0.24 mL, 2.60 mmol) and Et₃N (0.67 mL, 4.74 mmol) in CH₂Cl₂(10.0 mL) to give Intermediate CB1 (150 mg 27%) as a pale brown gum. ¹HNMR (CDCl₃): 7.58 (t, J = 7.6 Hz; 1H), 7.20 (d, J = 8.2 Hz; 1H), 7.11(d, J = 7.4 Hz; 1H), 3.88 (s, 2H), 3.71 (t, J = 6.2 Hz; 2H), 3.40 (s,3H), 3.0 (t, J = 6.4 Hz; 2H). Mass (M + H): 229.0. CB2

Intermediate CA2 (360 mg, 2.30 mmol) was reacted with methoxyacetylchloride (0.24 mL, 2.54 mmol) and Et₃N (0.65 mL, 4.61 mmol) in CH₂Cl₂(10.0 mL) to give Intermediate CB2 (190 mg 35%) as a pale brown gum. ¹HNMR (CDCl₃): 8.31 (t, J = 4.9 Hz; 1H), 7.19 (s, 1H), 7.08 (d, J = 4.56Hz; 1H), 6.61 (bs, 1H), 3.88 (s, 2H), 3.58 (t, J = 6.6 Hz; 2H), 3.38 (s,3H), 2.86 (t, J = 7.2 Hz: 2H). Mass (M + H): 229.0. CB3

Intermediate CA3 (1 g, 6.41 mmol) was reacted with methoxyacetylchloride (0.65 mL, 7.05 mmol) and Et₃N (1.79 mL, 12.8 mmol) in CH₂Cl₂(20.0 mL) to give Intermediate CB3 (700 mg 50%) as a pale brown gum. ¹HNMR (CDCl₃): δ 8.23 (d,, J = 2.48 Hz; 1H), 7.52 (dd, J = 8.2, 2.48 Hz;1H), 7.28 (d, J = 7.87 Hz, 1H), 6.61 (bs, 1H), 3.87 (s, 2H), 3.55 (q, J= 6.6 Hz; 2H), 3.38 (s, 3H), 3.00 (t, J = 6.42 Hz; 2H). Mass (M + H):229.0.

Preparation of Compounds (33)-(35)

To a solution of Intermediate CB (1.0 mmol) in toluene (10 mL) wereadded sequentially NaOtBu (1.4 mmol), (±) BINAP (0.02 mmol), Pd₂(dba)₃(0.01 mmol), and benzophenone imine (1.2 mmol). The mixture was degassedwith argon for 30 minutes and stirred at 80° C. for 6 hours. Thereaction mixture was concentrated, and the crude imine was purified bycolumn chromatography (silica gel 100-200 mesh) using 20% MeOH inchloroform as the eluent. The resulting intermediate was dissolved inMeOH (15 mL), and a hydroxylamine solution (50% in water; 1.2 mmol) wasadded, and the mixture was stirred at room temperature for 3 hours. Thereaction mixture was concentrated; the resulting aqueous residue wasthen diluted with water (10 mL) and extracted ethyl acetate (2×15 mL).The combined ethyl acetate layers were washed with water (10 mL) andbrine (15 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude product, which was purified using PREP TLC byeluting with 3% MeOH in chloroform. The product amine was treated withEtOAc.HCl and Compounds (33)-(35) were obtained as the corresponding HClsalt (Table 22).

TABLE 22 (33)

Intermediate CB1 (200 mg, 0.87 mmol) was reacted with NaOtBu (117 mg,1.22 mmol), (±) BINAP (11 mg, 0.017 mmol), Pd₂(dba)₃ (9 mg, 0.008 mmol),benzophenone imine (0.18 mL, 1.1 mmol), toluene (4.0 mL), and NH₂OH (0.2mL) in MeOH (2.0 mL) to give Compound (33)•HCl. Yield: 35 mg (20.5%)Pale brown solid. ¹H NMR (DMSO- d₆): δ 13.84 (bs, 1H), 8.00 (t, J = 5.49Hz; 1H), 7.82-7.78 (m, 2H), 6.82 (d, J = 8.79 Hz; 1H), 6.65 (d, J = 7.47Hz; 1H), 3.75 (s, 2H), 3.47-3.41 (m, 4H), 3.25 (s, 3H), 2.85 (t, J =6.59 Hz; 2H). Mass (M + H): 210.0. IR (cm⁻¹): 3422, 3316, 3145, 1660,1557, 1118, 790. HPLC purity (%): 98.9 (Max plot), 96.95 (254 nm), 98.91(215 nm). (34)

Intermediate CB2 (200 mg, 0.87 mmol) was reacted with NaOtBu (117 mg,1.22 mmol), (±) BINAP (11 mg, 0.017 mmol), Pd₂(dba)₃ (9 mg, 0.008 mmol),benzophenone imine (0.18 mL, 1.1 mmol), toluene (4.0 mL), and NH₂OH (0.2mL) in MeOH (2.0 mL) to give Compound (34)•HCl. Yield: 40 mg (18.5%) asa pale brown gum. ¹H NMR (DMSO-d₆): δ 13.52 (bs, 1H), 8.96 (bs, 2H),7.86 (d, J = 7.04 Hz; 1H), 6.74 (d, J = 4.97 Hz; 1H), 3.76 (s, 2H),3.42-3.34 (m, 3H), 3.27 (s, 3H), 2.76 (t, J = 6.84 Hz; 2H). Mass (M +H): 210.0. IR(cm⁻¹): 3367, 2926, 1662, 1550, 1114, 815. HPLC purity (%):94.32 (Max plot), 92.04 (215 nm). (35)

Intermediate CB3 (400 mg, 1.75 mmol) was reacted with NaOtBu (236.6 mg,2.45 mmol), (±) BINAP (21.8 mg, 0.035 mmol), Pd₂(dba)₃ (18.1 mg, 0.017mmol), benzophenone imine (0.35 mL, 2.10 mmol), toluene (8.0 mL), andNH₂OH (0.5 mL) in MeOH (4.0 mL) to give Compound (35)•HCl. Yield: 35 mg(16.5%) Pale brown solid. ¹H NMR (DMSO-d₆): δ 13.65 (bs, 1H), 7.90-7.75(m, 5H), 6.94 (d, J = 9.23 Hz; 1H), 3.75 (s, 2H), 3.38-3.26 (m, 5H),2.76 (t, J = 6.59 Hz; 2H). Mass (M + H): 210.0. IR (cm⁻¹): 3415, 1668,1630, 1115, 591. HPLC purity (%): 98.74 (Max plot), 96.57 (254 nm),98.61 (215 nm).Synthesis of Compounds (36)-(39)

Compounds (36)-(39) were synthesized according to the procedure shown inScheme 26.

Preparation of Intermediate CD

To a cold (0° C.) solution of Intermediate CC (1.0 mmol) andtriethylamine (1.2 mmol) in dichloromethane (20 mL) was added slowly therequisite sulfonyl chloride (1.2 mmol) over 5 minutes. After theaddition was complete, the reaction mixture was allowed to reach roomtemperature and stirred for 3 hours. The reaction mixture was thendiluted with dichloromethane (25 mL), washed with water (2×25 mL) andbrine (20 mL), dried over anhydrous Na₂SO₄, and the solvent was removedto afford the crude Intermediate CD (Table 23), which was purified bycolumn chromatography (silica gel 100-200 mesh) using 2% MeOH inchloroform as the eluent.

TABLE 23 CD1

Intermediate CC (250 mg, 1.65 mmol) was reacted with methanesulfonylchloride (0.15 mL, 1.92 mmol) and Et₃N (0.28 mL, 1.99 mmol) in CH₂Cl₂(5.0 mL) to give Intermediate CD1 (350 mg, 92%) as a pale brown oil. ¹HNMR (CDCl₃): 7.24 (m, 1H), 6.80- 6.75 (m, 3H), 4.22 (bs, 1H), 3.80 (s,3H), 3.43-3.38 (m, 2H), 2.87-2.84 (m, 5H). Mass (M + H): 230.0. CD2

Intermediate CC (250 mg, 1.65 mmol) was reacted with ethanesulfonylchloride (0.18 mL, 1.89 mmol) and Et₃N (0.27 mL, 1.92 mmol) in CH₂Cl₂(5.0 mL) to give Intermediate CD2 (320 mg, 81%) as a pale brown oil. ¹HNMR (CDCl₃): 7.26-7.22 (m, 1H), 6.81-6.75 (m, 3H), 4.05 (bs, 1H), 3.80(s, 3H), 3.41- 3.36 (m, 2H), 2.97 (q, 2H), 2.85(t, J = 6.6 Hz; 2H), 1.26(t, J = 6.6 Hz; 3H). Mass (M − H): 242.0. CD3

Intermediate CC (250 mg, 1.65 mmol) was reacted with isopropylsulfonylchloride (0.22 mL, 1.96 mmol) and Et₃N (0.28 mL, 1.97 mmol) in CH₂Cl₂(5.0 mL) to give Intermediate CD3 (340 mg, 82%) as a pale brown oil. ¹HNMR (CDCl₃): 7.24 (t, J = 7.5 Hz; 1H), 6.80-6.75 (m, 3H), 3.98 (bs, 1H),3.80 (s, 3H), 3.39 (q, 2H), 3.12-3.08 (m, 1H), 2.85 (t, J = 6.8 Hz; 2H),1.32 (s, 3H), 1.30 (s, 3H),. Mass (M − H): 242.1. Mass (M + H): 258.0.CD4

Intermediate CC (100 mg, 0.66 mmol) was reacted with isobutylsulfonylchloride (0.11 mL, 0.78 mmol) and triethylamine (0.11 mL, 0.78 mmol) indichloromethane (5.0 mL) to give Intermediate CD4 (130 mg, 72%) as apale brown oil. ¹H NMR (CDCl₃): 7.24 (t, J = 7.8 Hz; 1H), 6.80-6.74 (m,3H), 4.15 (bs, 1H), 3.80 (s, 3H), 3.37 (q, 2H), 2.86-2.80 (m, 4H), 2.17(m, 1H), 1.06 (s, 3H), 1.04 (s, 3H). Mass (M + H): 272.0.

Preparation of Compounds (36)-(39)

To a cold (−70° C.) solution of Intermediate CD (1.0 mmol) indichloromethane (20 mL) was added slowly BBr₃ (1.3 mmol). After theaddition was complete, the reaction mixture was allowed to reach 0° C.and stirred for 2 hours. The reaction mixture was quenched with ice coldwater (15 mL) and extracted with dichloromethane (2×30 mL). The combineddichloromethane layers were washed with water (2×10 mL) and brine (20mL), dried over anhydrous Na₂SO₄, and the solvent was removed to affordthe crude product (Table 24). This material was then purified by columnchromatography (silica gel 100-200 mesh) using 40% ethyl acetate inpetroleum ether as the eluent to afford the desired product.

TABLE 24 (36)

Intermediate CD1 (350 mg, 1.52 mmol) was reacted with BBr₃ (0.18 mL,1.89 mmol) in dichloromethane (6.0 mL) to give Compound (36) (220 mg,66%) as a pale brown gum. ¹H NMR (CDCl₃): δ 7.19 (t, J = 7.80 Hz; 1H),6.78- 6.69 (m, 3H), 4.81 (s, 1H), 4.19 (bs, 1H), 3.42- 3.38 (m, 2H),2.88- 2.81 (m, 5H). Mass (M − H): 214.0. IR (cm⁻¹): 3434, 2930, 1597,1311, 1144, 973, 521. HPLC purity (%): 97.01 (Max plot), 96.81 (215 nm).(37)

Intermediate CD2 (320 mg, 1.31 mmol) was reacted with BBr₃ (0.16 mL,1.68 mmol) in dichloromethane (5.0 mL) to give Compound (37) (260 mg,86%) as a pale brown oil. ¹H NMR (CDCl₃): δ 7.18 (t, J = 7.71 Hz; 1H),6.76- 6.71 (m, 3H), 5.43 (s, 1H), 4.28 (t, J = 5.85 Hz; 1H), 3.39-3.34(m, 2H), 2.98-2.93 (m, 2H), 2.84-2.79 (m, 2H), 1.27 (t, J = 7.32 Hz;3H),. Mass (M − H): 214.0. IR (cm⁻¹): 3402, 3294, 2931, 1589, 1456,1312, 1137, 869, 697. HPLC purity (%): 97.63 (Max plot), 97.04 (215 nm).(38)

Intermediate CD3 (340 mg, 1.32 mmol) was reacted with BBr₃ (0.16 mL,1.71 mmol) in dichloromethane (5.0 mL) to give Compound (38) (285 mg,89%) as a pale brown oil. ¹H NMR (CDCl₃): δ 7.19 (t, J = 7.87 Hz; 1H),6.79- 6.70 (m, 3H), 4.86 (s, 1H), 3.95 (bs, 1H), 3.41-3.36 (q, 2H),3.12- 3.09 (m, 1H), 2.83 (t, J = 6.63 Hz; 2H), 1.32 (s, 3H), 1.30 (s,3H),. Mass (M − H): 242.1. IR (cm⁻¹): 3414, 2928, 1589, 1456, 1308,1132, 885, 783, 696. HPLC purity (%): 94.44 (Max plot), 93.92 (215 nm).(39)

Intermediate CD4 (130 mg, 0.47 mmol) was reacted with BBr₃ (0.06 mL,0.61 mmol) in dichloromethane (5.0 mL) to give Compound (39) (110 mg,89%) as a pale brown oil. ¹H NMR (CDCl₃): δ 7.19 (t, 1H), 6.69 (m, 3H),4.83 (s, 1H), 4.05 (t, 1H), 3.38 (q, 2H), 2.84-2.81 (m, 4H), 2.2 (m,1H), 1.06 (s, 3H), 1.05 (s, 3H),. Mass (M − H): 256.1. IR (cm⁻¹): 3413,2963, 1589, 1457, 1308, 1139, 869, 784, 696. HPLC purity (%): 97.14 (Maxplot), 97.28 (215 nm).Screening Conditions for Identifying SPR Inhibition

The compounds described herein were screened for activity as inhibitorsof Sepiapterin Reductase (SPR).

Protein Production

His-tagged recombinant human SPR (GenBank accession number:NM_(—)003124) was cloned as synthetic gene and expressed in E. coliRosetta 2 strain. Bacteria were grown at 37° C., and expression of SPRprotein was induced for 4 hours. After cell lysis, the His-tagged SPRprotein was affinity purified with a TALON column (purity of theisolated SPR protein is >95%). In an initial quality control, theenzymatic activity of recombinant SPR was confirmed with a chromogenicassay (read-out OD at 420 nm).

Primary Screen

To screen for SPR inhibition, a biochemical assay based on LC/MS (andchromogenic) read-out has been developed. The LC/MS assay monitors theproduct formation (L-biopterin) and the chromogenic assay measures OD at420 nm.

N-methoxyacetyl serotonin was used as a reference compound (positivecontrol). The IC₅₀ measured using the screening conditions was 20-40 nM,which agrees with the literature (Smith et al., Journal of BiologicalChemistry, 297:5601, 1992).

The exemplary assay protocol uses the following conditions: SPR (6 nM);L-Sepiapterin (50 μM); NADPH (100 μM); Na-Phosphate buffer, pH 6.5 (100mM); 82 μL assay volume; 60 minutes incubation with compounds (0.5%final concentration in DMSO) at 37° C. in Greiner μClear® 384 wellplates.

The following experimental procedure was applied:

-   -   (1) Add 2 μL compound (inhibitor) dilutions (20% DMSO) in        Greiner μClear® 384 well plates.    -   (2) Add 40 μL enzyme/assay buffer.    -   (3) Start: 40 μL substrate solution/assay buffer.    -   (4) Final: 82 μL assay solution.    -   (5) Incubation: Safire 1 hour at 37° C. and measuring after 1        hour using OD at 420 nm (chromogenic read-out).    -   (6) Transfer 50 μL to a 384 Matrix flat bottom (clear) for LC/MS        measurement.    -   (7) Stop: add 5 μL 1M HCl and 10 μL of 0.1 M I₂/NaI solution.    -   (8) Incubation: 45 minutes at 37° C.    -   (9) Neutralization: 10 μL 0.1 M ascorbic acid and 5 μL 1 N NaOH.    -   (10) LC/MS measurement.

If desired, the compounds can be been further screened using an 8 pointdilution series to validate the results. For example, the compounds ofTable 1 were screened using this additional method in triplicate. Thesetests were performed at the following concentrations:

-   -   Most potent: 0.2-0.7-2.1-6.2-18.5-55.6-166.7-500 nM    -   Medium potent: 0.002-0.007-0.02-00.6-0.02-0.7-1.7-5 μM    -   Less potent: 0.02-0.07-0.2-0.6-1.9-5.6-16.7-50 μM

A robust performance of the SPR assay was achieved throughout thescreen, resulting in a mean Z′-value of 0.93 (chromogenic) and 0.82(LC/MS), and the inhibitors showed the expected response in the LC/MS(chromogenic) assay.

Screening of the compounds has been performed at three concentrations(20 nM, 200 nM, and 2000 nM) in singletons (0.5% final concentration inDMSO). Z′ was 0.91 and 0.81 for the chromogenic and the LC/MSmeasurements, respectively. The screens showed that compounds ofFormulas (I) and (II) can inhibit SPR, even at the lower concentrations.For example, at the 20 nM concentration, up to 77% inhibition of enzymeactivity was observed. Exemplary IC₅₀ values are presented in Table 25.

TABLE 25 IC₅₀ chromogenic IC₅₀ LC/MS No. Structure [μM] [μM] controlN-Methoxyacetyl-Serotonin 0.042 0.043  (1)

0.40 0.33  (2)

0.36 0.34  (3)

2.8 2.2 (16)

3.4 2.8 (17)

4.5 3.2 (18)

1.1 1.0 (21)

0.084 0.086 (22)

0.011 0.019 (23)

0.011 0.012 (24)

0.31 0.31 (32)

0.064 0.069 (12)

2.1 1.6Other Embodiments

While the invention has been described in connection with specificembodiments thereof, it will be understood that it is capable of furthermodifications and this application is intended to cover any variations,uses, or adaptations of the invention following, in general, theprinciples of the invention and including such departures from thepresent disclosure that come within known or customary practice withinthe art to which the invention pertains and may be applied to theessential features hereinbefore set forth.

All references, patents, patent application publications, and patentapplications cited herein are hereby incorporated by reference to thesame extent as if each of these references, patents, patent applicationpublications, and patent applications were separately incorporated byreference herein.

What is claimed is:
 1. A compound of Formula (1):

wherein, X¹ and X² are independently selected from N, C—H, andC-halogen; R² is CH₂OR^(2A) or C₁₋₆ alkyl; R^(2A) is H or C₁₋₆ alkyl;R^(3A) and R^(3B) are both H; R^(4A) and R^(4B) are both H; and R⁵ andR⁶ are independently selected from the group consisting of H and C₁₋₆alkyl wherein the alkyl may be unsubstituted or substituted one or moretimes with groups independently selected from the group consisting of:C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, cycloalkyl, cycloalkenyl,heterocyclyl, aryl, heteroaryl, halogen; azido(—N₃), nitro (—NO₂), cyano(—CN), acyloxy(—OC(═O)R′), acyl (—C(═O)R′), alkoxy (—OR′), amido(—NR′C(═O)R″ or —C(═O)NRR′), amino (—NRR′), carboxylic acid (—CO₂H),carboxylic ester (—CO₂R′), carbamoyl (—OC(═O)NR′R″ or —NRC(═O)OR′),hydroxy (—OH), isocyano (—NC), sulfonate (—S(═O)₂OR), sulfonamide(—S(═O)₂NRR′ or —NRS(═O)₂R′), or sulfonyl (—S(═O)₂R), where each R or R′is selected, independently, from H, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂ ₋₆alkynyl, cycloalkyl, heterocyclyl, aryl, and heteroaryl; or the compoundis a pharmaceutically acceptable salt thereof.
 2. The compound of claim1, wherein one or both of X¹ and X² is C—H.
 3. The compound of claim 1,wherein both of X¹ and X² are C—H.
 4. A compound of Formula (I):

wherein, one or both of X¹ and X² is C—Cl; R² is CH₂OR^(2A) or C₁₋₆alkyl; R^(2A) is H or C₁₋₆ alkyl; R^(3A) and R^(3B) are both H; R^(4A)and R^(4B) are both H; and R⁵ and R⁶ are independently selected from thegroup consisting of H and C₁₋₆ alkyl; wherein said C₁₋₆ alkyl may beunsubstituted or substituted one or more times with groups independentlyselected from the group consisting of: C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, heteroaryl,halogen; azido(—N₃), nitro (—NO₂), cyano (—CN), acyloxy(—OC(═O)R′), acyl(—C(═O)R′), alkoxy (—OR′), amido (—NR′C(═O)R″ or —C(═O)NRR′), amino(—NRR′), carboxylic acid (—CO₂H), carboxylic ester (—CO₂R′), carbamoyl(—OC(═O)NR′R″ or —NRC(═O)OR′), hydroxy (—OH), isocyano (—NC), sulfonate(—S(═O)₂OR), sulfonamide (—S(═O)₂NRR′ or —NRS(═O)₂R′), or sulfonyl(—S(═O)₂R), where each R or R′ is selected, independently, from H, C₁₋₆alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, cycloalkyl, heterocyclyl, aryl, andheteroaryl; or the compound is a pharmaceutically acceptable saltthereof.
 5. The compound of claim 3, wherein R⁵ and R⁶ are independentlyselected from H and CH₃.
 6. A compound of Formula (1):

wherein, X¹and X² are independently selected from N, C—H, and C-halogen;R² is CH₂OR^(2A); R^(2A) is H or C₁₋₆ alkyl; R^(3A) and R^(3B) are bothH; R^(4A) and R^(4B) are both H; and R⁵ and R⁶ are independentlyselected from the group consisting of H and C₁₋₆ alkyl; wherein the C₁₋₆alkyl may be unsubstituted or substituted one or more times with groupsindependently selected from the group consisting of: C₁₋₆ alkyl, C₂₋₆alkenyl, C₂₋₆ alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl,heteroaryl, halogen; azido(—N₃), nitro (—NO₂), cyano (—CN),acyloxy(—OC(═O)R′), acyl (—C(═O)R′), alkoxy (—OR′), amido (—NR′C(═O)R″or —C(═O)NRR′), amino (—NRR′), carboxylic acid (—CO₂H), carboxylic ester(—CO₂R′), carbamoyl (—OC(═O)NR′R″ or —NRC(═O)OR′), hydroxy (—OH),isocyano (—NC), sulfonate (—S(═O)₂OR), sulfonamide (—S(═O)₂NRR′ or—NRS(═O)₂R′), or sulfonyl (—S(═O)₂R), where each R or R′ is selected,independently, from H, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl,cycloalkyl, heterocyclyl, aryl, and heteroaryl; or the compound is apharmaceutically acceptable salt thereof.
 7. A compound of Formula (1):

wherein, both of X¹ and X² is C—H; R² is CH₂OR^(2A); R^(2A) is H or C₁₋₆alkyl; R^(3A) and R^(3B) are both H; R^(4A) and R^(4B) are both H; andR⁵ and R⁶ are independently selected from the group consisting of H andC₁₋₆ alkyl; wherein the aid C₁₋₆ alkyl may be unsubstituted orsubstituted one or more times with groups independently selected fromthe group consisting of: C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl,cycloalkyl, cycloalkenyl, heterocyclyl, aryl, heteroaryl, halogen;azido(—N₃), nitro (—NO₂), cyano (—CN), acyloxy(—OC(═O)R′), acyl(—C(═O)R′), alkoxy (—OR′), amido (—NR′C(═O)R″ or —C(═O)NRR′), amino(—NRR′), carboxylic acid (—CO₂H), carboxylic ester (—CO₂R′), carbamoyl(—OC(═O)NR′R″ or —NRC(═O)OR′), hydroxy (—OH), isocyano (—NC), sulfonate(—S(═O)₂OR), sulfonamide (—S(═O)₂NRR′ or —NRS(═O)₂R′), or sulfonyl(—S(═O)₂R), where each R or R′ is selected, independently, from H, C₁₋₆alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, cycloalkyl, heterocyclyl, aryl, andheteroaryl; or the compound is a pharmaceutically acceptable saltthereof.
 8. A compound selected from:


9. A compound selected from:


10. A compound of Formula I-B:

wherein, R¹ is OH; R² is C₃₋₆ alkyl; R⁵ is CH₃; and R⁶ is independentlyselected from the group consisting of H or C₁₋₃ alkyl; wherein the C₃₋₆or C₁₋₃ alkyl may be unsubstituted or substituted one or more times withgroups independently selected from the group consisting of: C₁₋₆ alkyl,C₂₋₆ alkenyl, C₂₋₆ alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl,aryl, heteroaryl, halogen; azido(—N₃), nitro (—NO₂), cyano (—CN),acyloxy(—OC(═O)R′), acyl (—C(═O)R′), alkoxy (—OR′), amido (—NR′C(═O)R″or —C(═O)NRR′), amino (—NRR′), carboxylic acid (—CO₂H), carboxylic ester(—CO₂R′), carbamoyl (—OC(═O)NR′R″ or —NRC(═O)OR′), hydroxy (—OH),isocyano (—NC), sulfonate (—S(═O)₂OR), sulfonamide (—S(═O)₂NRR′ or—NRS(═O)₂R′), or sulfonyl (—S(═O)₂R), where each R or R′ is selected,independently, from H, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl,cycloalkyl, heterocyclyl, aryl, and heteroaryl.
 11. The compound ofclaim 1, wherein said compound is an inhibitor of Sepiapterin Reductase(SPR).
 12. A pharmaceutical composition comprising the compound of claim1, or a prodrug or pharmaceutically acceptable salt thereof, and apharmaceutically acceptable excipient.
 13. A method of treating orreducing pain in a mammal, wherein said method comprises theadministration of the compound of claim 1, or a prodrug orpharmaceutically acceptable salt thereof to the mammal in a dosagesufficient to inhibit SPR.
 14. The method of claim 13, wherein said painis neuropathic, inflammatory, nociceptive, or functional pain.
 15. Themethod of claim 13, wherein said pain is chronic pain.
 16. The method ofclaim 13, wherein said pain is acute pain.